For providers

Active adversaries use the same division-of-labor tactics common among most mature organizations.

President Joe Biden has signed an executive order aimed at safeguarding the personal data of American citizens from countries of concern.

Sandvine, a network intelligence firm based in Ontario, Canada, that specializes in network policy control products, was subjected to government restrictions.

Sen. Edward Markey, D-Mass., urged Federal Trade Commission Chair Lina Khan through a letter on Wednesday to probe into the data privacy practices of automotive manufacturers.

Under the integration, JFrog Artifactory and Xray will integrate natively with Qwak’s ML Platform in a modern DevSecOps and MLOps workflow.

SUMMARY Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources. The Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), and the Multi-State Information Sharing and Analysis Center (MS-ISAC) are releasing this joint CSA, to disseminate known TTPs and IOCs associated with the Phobos ransomware variants observed as recently as February 2024, according to open source reporting. Phobos is structured as a ransomware-as-a-service (RaaS) model. Since May 2019, Phobos ransomware incidents impacting state, local, tribal, and territorial (SLTT) governments have been regularly reported to the MS-ISAC. These incidents targeted municipal and county governments, emergency services, education, public healthcare, and other critical infrastructure entities to successfully ransom several million U.S. dollars.[ 1],[ 2] The FBI, CISA, and the MS-ISAC encourage organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of Phobos ransomware and other ransomware incidents. Download the PDF version of this report: AA24-060A #StopRansomware: Phobos Ransomware (PDF, 677.95 KB ) For a downloadable copy of indicators of compromise (IOCs), see: AA24-060A STIX XML (XML, 147.73 KB ) AA24-060A STIX JSON (JSON, 119.53 KB ) TECHNICAL DETAILS Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 14. See the MITRE ATT&CK Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool. Overview According to open source reporting, Phobos ransomware is likely connected to numerous variants (including Elking, Eight, Devos, Backmydata, and Faust ransomware) due to similar TTPs observed in Phobos intrusions. Phobos ransomware operates in conjunction with various open source tools such as Smokeloader, Cobalt Strike, and Bloodhound. These tools are all widely accessible and easy to use in various operating environments, making it (and associated variants) a popular choice for many threat actors.[ 3],[ 4] Reconnaissance and Initial Access Phobos actors typically gain initial access to vulnerable networks by leveraging phishing campaigns [ T1598] to drop hidden payloads or using internet protocol (IP) scanning tools, such as Angry IP Scanner, to search for vulnerable Remote Desktop Protocol (RDP) ports [ T1595.001] or by leveraging RDP on Microsoft Windows environments.[ 5],[ 6] Once they discover an exposed RDP service, the actors use open source brute force tools to gain access [ T1110]. If Phobos actors gain successful RDP authentication [ T1133][ T1078] in the targeted environment, they perform open source research to create a victim profile and connect the targeted IP addresses to their associated companies [ T1593]. Threat actors leveraging Phobos have notably deployed remote access tools to establish a remote connection within the compromised network [ T1219].[ 7] Alternatively, threat actors send spoofed email attachments [ T1566.001] that are embedded with hidden payloads [ T1204.002] such as SmokeLoader, a backdoor trojan that is often used in conjunction with Phobos. After SmokeLoader’s hidden payload is downloaded onto the victim’s system, threat actors use the malware’s functionality to download the Phobos payload and exfiltrate data from the compromised system. Execution and Privilege Escalation Phobos actors run executables like 1saas.exe or cmd.exe to deploy additional Phobos payloads that have elevated privileges enabled [ TA0004]. Additionally, Phobos actors can use the previous commands to perform various windows shell functions. The Windows command shell enables threat actors to control various aspects of a system, with multiple permission levels required for different subsets of commands [ T1059.003][ T1105].[ 8] Smokeloader Deployment Phobos operations feature a standard three phase process to decrypt a payload that allows the threat actors to deploy additional destructive malware.[ 9] For the first phase, Smokeloader manipulates either VirtualAlloc or VirtualProtect API functions—which opens an entry point, enabling code to be injected into running processes and allowing the malware to evade network defense tools [ T1055.002]. In the second phase, a stealth process is used to obfuscate command and control (C2) activity by producing requests to legitimate websites [ T1001.003].[ 10] Within this phase, the shellcode also sends a call from the entry point to a memory container [ T1055.004] and prepares a portable executable for deployment in the final stage [ T1027.002][ T1105][ T1140]. Finally, once Smokeloader reaches its third stage, it unpacks a program-erase cycle from stored memory, which is then sent to be extracted from a SHA 256 hash as a payload.[ 7] Following successful payload decryption, the threat actors can begin downloading additional malware. Additional Phobos Defense Evasion Capabilities Phobos ransomware actors have been observed bypassing organizational network defense protocols by modifying system firewall configurations using commands like netsh firewall set opmode mode=disable [ T1562.004]. Additionally, Phobos actors can evade detection by using the following tools: Universal Virus Sniffer, Process Hacker, and PowerTool [ T1562]. Persistence and Privilege Escalation According to open source reporting, Phobos ransomware uses commands such as Exec.exe or the bcdedit[.]exe control mechanism. Phobos has also been observed using Windows Startup folders and Run Registry Keys such as C:/Users\Admin\AppData\Local\directory [ T1490][ T1547.001] to maintain persistence within compromised environments.[ 5] Additionally, Phobos actors have been observed using built-in Windows API functions [ T1106] to steal tokens [ T1134.001], bypass access controls, and create new processes to escalate privileges by leveraging the SeDebugPrivilege process [ T1134.002]. Phobos actors attempt to authenticate using cached password hashes on victim machines until they reach domain administrator access [ T1003.005]. Discovery and Credential Access Phobos actors additionally use open source tools [ T1588.002] such as Bloodhound and Sharphound to enumerate the active directory [ T1087.002]. Mimikatz and NirSoft, as well as Remote Desktop Passview to export browser client credentials [ T1003.001][ T1555.003], have also been used. Furthermore, Phobos ransomware is able to enumerate connected storage devices [ T1082], running processes [ T1057], and encrypt user files [ T1083]. Exfiltration Phobos actors have been observed using WinSCP and Mega.io for file exfiltration.[ 11] They use WinSCP to connect directly from a victim network to an FTP server [ T1071.002] they control [ TA0010]. Phobos actors install Mega.io [ T1048] and use it to export victim files directly to a cloud storage provider [ T1567.002]. Data is typically archived as either a .rar or .zip file [ T1560] to be later exfiltrated. They target legal documentation, financial records, technical documents (including network architecture), and databases for commonly used password management software [ T1555.005]. Impact After the exfiltration phase, Phobos actors then hunt for backups. They use vssadmin.exe and Windows Management Instrumentation command-line utility (WMIC) to discover and delete volume shadow copies in Windows environments. This prevents victims from recovering files after encryption has taken place [ T1047][ T1490]. Phobos.exe contains functionality to encrypt all connected logical drives on the target host [ T1486]. Each Phobos ransomware executable has unique build identifiers (IDs), affiliate IDs, as well as a unique ransom note which is embedded in the executable. After the ransom note has populated on infected workstations, Phobos ransomware continues to search for and encrypt additional files. Most extortion [ T1657] occurs via email; however, some affiliate groups have used voice calls to contact victims. In some cases, Phobos actors have used onion sites to list victims and host stolen victim data. Phobos actors use various instant messaging applications such as ICQ, Jabber, and QQ to communicate [ T1585]. See Figure 2 for a list of email providers used by the following Phobos affiliates: Devos, Eight, Elbie, Eking, and Faust.[ 6] INDICATORS OF COMPROMISE (IOCs) See Table 1 through 6 for IOCs obtained from CISA and the FBI investigations from September through November 2023. Table 1: Associated Phobos Domains Associated Phobos Domains adstat477d[.]xyz demstat577d[.]xyz [ 12] serverxlogs21[.]xyz Table 2: Observed Phobos Shell Commands Shell Commands vssadmin delete shadows /all /quiet [ T1490] netsh advfirewall set currentprofile state off wmic shadowcopy delete netsh firewall set opmode mode=disable [ T1562.004] bcdedit /set {default} bootstatuspolicy ignoreallfailures [ T1547.001] bcdedit /set {default} recoveryenabled no [ T1490] wbadmin delete catalog -quiet mshta C:\%USERPROFILE%\Desktop\info.hta [ T1218.005] mshta C:\%PUBLIC%\Desktop\info.hta mshta C:\info.hta The commands above are observed during the execution of a Phobos encryption executable. A Phobos encryption executable spawns a cmd.exe process, which then executes the commands listed in Table 1 with their respective Windows system executables. When the commands above are executed on a Windows system, volume shadow copies are deleted and Windows Firewall is disabled. Additionally, the system’s boot status policy is set to boot even when there are errors during the boot process, and automatic recovery options, like Windows Recovery Environment (WinRE), are disabled for the given boot entry. The system’s backup catalog is also deleted. Finally, the Phobos ransom note is displayed to the end user using mshta.exe. Table 3: Observed Phobos Registry Keys Registry Keys HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\ C:/Users\Admin\AppData\Local\directory Table 4: Observed Phobos Actor Email Addresses Email Addresses AlbetPattisson1981@protonmail[.]com henryk@onionmail[.]org atomicday@tuta[.]io info@fobos[.]one axdus@tuta[.]io it.issues.solving@outlook[.]com barenuckles@tutanota[.]com JohnWilliams1887@gmx[.]com Bernard.bunyan@aol[.]com jonson_eight@gmx[.]us bill.g@gmx[.]com joshuabernandead@gmx[.]com bill.g@msgsafe[.]io LettoIntago@onionmail[.]com bill.g@onionmail[.]org Luiza.li@tutanota[.]com bill.gTeam@gmx[.]com MatheusCosta0194@gmx[.]com blair_lockyer@aol[.]com mccreight.ellery@tutanota[.]com CarlJohnson1948@gmx[.]com megaport@tuta[.]io cashonlycash@gmx[.]com miadowson@tuta[.]io chocolate_muffin@tutanota[.]com MichaelWayne1973@tutanota[.]com claredrinkall@aol[.]com normanbaker1929@gmx[.]com clausmeyer070@cock[.]li nud_satanakia@keemail[.]me colexpro@keemail[.]me please@countermail[.]com cox.barthel@aol[.]com precorpman@onionmail[.]org crashonlycash@gmx[.]com recovery2021@inboxhub[.]net everymoment@tuta[.]io recovery2021@onionmail[.]org expertbox@tuta[.]io SamuelWhite1821@tutanota[.]com fastway@tuta[.]io SaraConor@gmx[.]com fquatela@techie[.]com secdatltd@gmx[.]com fredmoneco@tutanota[.]com skymix@tuta[.]io getdata@gmx[.]com sory@countermail[.]com greenbookBTC@gmx[.]com spacegroup@tuta[.]io greenbookBTC@protonmail[.]com stafordpalin@protonmail[.]com helperfiles@gmx[.]com starcomp@keemail[.]me helpermail@onionmail[.]org xdone@tutamail[.]com helpfiles@onionmail[.]org xgen@tuta[.]io helpfiles102030@inboxhub[.]net xspacegroup@protonmail[.]com helpforyou@gmx[.]com zgen@tuta[.]io helpforyou@onionmail[.]org zodiacx@tuta[.]io Table 5: Observed Phobos Actor Telegram Username Telegram Username @phobos_support Table 6: Observed Phobos Actor Wickr Address Wickr Address Vickre me Disclaimer: Organizations are encouraged to investigate the use of the IOCs in Table 7 for related signs of compromise prior to performing remediation actions. Table 7: Phobos IOCs from September through December 2023 Associated IP Address File Type File Name SHA 256 Hash 194.165.16[.]4 (October 2023) Win32.exe Ahpdate.exe [ 13] 0000599cbc6e5b0633c5a6261c79e4d3d81005c77845c6b0679d854884a8e02f 45.9.74[.]14 (December 2023) 147.78.47[.]224 (December 2023) Executable and Linkable Format (ELF) [ 14] 1570442295 (Trojan Linux Mirai) 7451be9b65b956ee667081e1141531514b1ec348e7081b5a9cd1308a98eec8f0 185.202.0[.]111 (September 2023) Win32.exe [ 15] cobaltstrike_shellcode[.]exe (C2 activity) 185.202.0[.]111 (December 2023) .txt [ 16] f1425cff3d28afe5245459afa6d7985081bc6a62f86dce64c63daeb2136d7d2c.bin (Trojan) Disclaimer: Organizations are encouraged to investigate the use of the file hashes in Tables 8 and 9 for related signs of compromise prior to performing remediation actions. Table 8: Phobos Actor File Hashes Observed in October 2023 Phobos Ransomware SHA 256 Malicious Trojan Executable File Hashes 518544e56e8ccee401ffa1b0a01a10ce23e49ec21ec441c6c7c3951b01c1b19c 9215550ce3b164972413a329ab697012e909d543e8ac05d9901095016dd3fc6c 482754d66d01aa3579f007c2b3c3d0591865eb60ba60b9c28c66fe6f4ac53c52 c0539fd02ca0184925a932a9e926c681dc9c81b5de4624250f2dd885ca5c4763 Table 9: Phobos Actor File Hashes from Open Source from November 2023 [ 17] Phobos Ransomware SHA 256 File Hashes 58626a9bfb48cd30acd0d95debcaefd188ae794e1e0072c5bde8adae9bccafa6 f3be35f8b8301e39dd3dffc9325553516a085c12dc15494a5e2fce73c77069ed 518544e56e8ccee401ffa1b0a01a10ce23e49ec21ec441c6c7c3951b01c1b19c 32a674b59c3f9a45efde48368b4de7e0e76c19e06b2f18afb6638d1a080b2eb3 2704e269fb5cf9a02070a0ea07d82dc9d87f2cb95e60cb71d6c6d38b01869f66 fc4b14250db7f66107820ecc56026e6be3e8e0eb2d428719156cf1c53ae139c6 a91491f45b851a07f91ba5a200967921bf796d38677786de51a4a8fe5ddeafd2 MITRE ATT&CK TECHNIQUES See Table 10 through 22 for all threat actor tactics and techniques referenced in this advisory. Table 10: Phobos Threat Actors ATT&CK Techniques for Enterprise – Reconnaissance Technique Title ID Use Search Open Websites/Domains T1593 Phobos actors perform open source research to find information about victims that can be used during targeting to create a victim profile. Scanning IP Blocks T1595.001 Phobos actors used IP scanning tools to include Angry IP Scanner to search for vulnerable RDP ports. Phishing for Information T1598 Phobos actors use phishing campaigns to social engineer information from users and gain access to vulnerable RDP ports. Table 11: Phobos Threat Actors ATT&CK Techniques for Enterprise – Resource Development Technique Title ID Use Establish Accounts T1585 Phobos actors establish accounts to communicate. Obtain Capabilities: Tool T1588.002 Phobos actors used open source tools in their attack. Table 12: Phobos Threat Actors ATT&CK Techniques for Enterprise – Initial Access Technique Title ID Use Valid Accounts T1078 Following successful RDP authentication, Phobos actors search for IP addresses and pair them with their associated computer to create a victim profile. External Remote Services T1133 Phobos actors may leverage external-facing remote services to initially access and/or persist within a network. Phishing: Spearphishing Attachment T1566.001 Phobos actors used a spoofed email attachment to execute attack. Table 13: Phobos Threat Actors ATT&CK Techniques for Enterprise – Execution Technique Title ID Use Windows Management Instrumentation T1047 Phobos actors used Windows Management Instrumentation command-line utility (WMIC) to prevent victims from recovering files. Windows Command Shell T1059.003 Phobos actors can use the previous commands to perform commands with windows shell functions. Native API T1106 Phobos actors used open source tools to enumerate the active directory. Malicious File T1204.002 Phobos actors attached a malicious email attachment to deliver ransomware. Table 14: Phobos Threat Actors ATT&CK Techniques for Enterprise – Persistence Technique Title ID Use Registry Run Keys / Startup Folder T1547.001 Phobos ransomware operates using the Exec.exe control mechanism and has been observed using Windows Startup folders and Run Registry Keys. Table 15: Phobos Threat Actors ATT&CK Techniques for Enterprise – Privilege Escalation Technique Title ID Use Privilege Escalation TA0004 Phobos actors use run commands like 1saas.exe, or cmd.exe to deploy additional Phobos payloads with escalated privileges. Portable Executable Injection T1055.002 Phobos actors use Smokeloader to inject code into running processes to identify an entry point through enabling a VirtualAlloc or VirtualProtect process. Asynchronous Procedure Call T1055.004 During phase two of execution, Phobos ransomware sends a call back from an identified entry point. Access Token Manipulation: Token Impersonation/Theft T1134.001 Phobos actors can use Windows API functions to steal tokens. Create Process with Token T1134.002 Phobos actors used Windows API functions to steal tokens, bypass access controls and create new processes. Table 16: Phobos Threat Actors ATT&CK Techniques for Enterprise – Defense Evasion Technique Title ID Use Software Packing T1027.002 Phobos actors deployed a portable executable (PE) to conceal code. Embedded Payloads T1027.009 Phobos actors embedded the ransomware as a hidden payload by using Smokeloader. Deobfuscate/Decode Files or Information T1140 During phase two of execution, Phobos actors’ malware stores and decrypts information. System Binary Proxy Execution: Mshta T1218.005 Phobos actors used Mshta to execute malicious files. Impair Defenses T1562 Phobos actors can use Universal Virus Sniffer, Process Hacker, and PowerTool to evade detection. Disable or Modify System Firewall T1562.004 Phobos ransomware has been observed bypassing organizational network defense protocols through modifying system firewall configurations. Table 17: Phobos Threat Actors ATT&CK Techniques for Enterprise – Credential Access Technique Title ID Use OS Credential Dumping: LSASS Memory T1003.001 Phobos actors used Mimikatz to export credentials. OS Credential Dumping: Cached Domain Credentials T1003.005 Phobos actors use cached domain credentials to authenticate as the domain administrator in the event a domain controller is unavailable. Brute Force T1110 Phobos actors may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained. Credentials from Password Stores T1555 Phobos actors may search for common password storage locations to obtain user credentials. Credentials from Password Stores: Credentials from Web Browsers T1555.003 Phobos actors use Nirsoft or Passview to export client credentials from web browsers. Phobos actors search for stored credentials in browser clients once they gain initial network access. Credentials from Password Stores: Password Managers T1555.005 Phobos actors targeted victim’s databases for password management software. Table 18: Phobos Threat Actors ATT&CK Techniques for Enterprise – Discovery Technique Title ID Use Process Discovery T1057 Phobos ransomware is able to run processes. System Information Discovery T1082 Phobos ransomware is able to enumerate connected storage devices. File and Directory Discovery T1083 Phobos ransomware can encrypt user files. Domain Account T1087.002 Phobos threat actor used Bloodhound and Sharphound to enumerate the active directory. Table 19: Phobos Threat Actors ATT&CK Techniques for Enterprise – Collection Technique Title ID Use Archive Collected Data T1560 Phobos threat actors archive data as either a .rar or .zip file to be later exfiltrated. Table 20: Phobos Threat Actors ATT&CK Techniques for Enterprise – Command and Control Technique Title ID Use Data Obfuscation: Protocol Impersonation T1001.003 Phobos actors used a stealth process to obfuscate C2 activity. File Transfer Protocols T1071.002 Phobos threat actors used WinSCP to connect the victim’s network to an FTP server. Ingress Tool Transfer T1105 Phobos ransomware extracts its final payload from the hashed file. Remote Access Software T1219 Phobos threat actors used remote access tools to establish a remote connection within victim’s network. Table 21: Phobos Threat Actors ATT&CK Techniques for Enterprise – Exfiltration Technique Title ID Use Exfiltration TA0010 Phobos threat actors may use exfiltration techniques to steal data from your network. Exfiltration Over Alternative Protocol T1048 Phobos threat actors use software to export files to a cloud. Exfiltration to Cloud Storage T1567.002 Phobos threat actors use Mega.io to exfiltrate data to a cloud storage service rather than over their primary command and control channel. Table 22: Phobos Threat Actors ATT&CK Techniques for Enterprise – Impact Technique Title ID Use Data Encrypted for Impact T1486 Phobos threat actors use the Phobos.exe command to encrypt data on all logical drives connected to the network. Inhibit System Recovery T1490 Phobos threat actors may delete or remove backups to include volume shadow copies from Windows environments to prevent victim data recovery response efforts. Financial Theft T1657 Phobos threat actor’s extort victims for financial gain. MITIGATIONS Secure by Design and Default Mitigations: These mitigations apply to all critical infrastructure organizations and network defenders. The FBI, CISA, and MS-ISAC recommend that software manufacturers incorporate secure by design and default principles and tactics into their software development practices limiting the impact of ransomware techniques, thus, strengthening the secure posture for their customers. For more information on secure by design, see CISA’s Secure by Design webpage and joint guide. The FBI, CISA, and MS-ISAC recommend organizations implement the mitigations below to improve your organization’s cybersecurity posture against actors’ activity. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections. Secure remote access software by applying recommendations from the joint Guide to Securing Remote Access Software. Implement application controls to manage and control execution of software, including allowlisting remote access programs. Application controls should prevent installation and execution of portable versions of unauthorized remote access and other software. A properly configured application allowlist solution will block any unlisted application execution. Allowlisting is important because antivirus solutions may fail to detect the execution of malicious portable executables when the files use any combination of compression, encryption, or obfuscation. Implement log collection best practices and use intrusion detection systems to defend against threat actors manipulating firewall configurations through early detection [ CPG 2.T]. Implement EDR solutions to disrupt threat actor memory allocation techniques. Strictly limit the use of RDP and other remote desktop services. If RDP is necessary, rigorously apply best practices, for example [ CPG 2.W]: Audit the network for systems using RDP. Close unused RDP ports. Enforce account lockouts after a specified number of attempts. Apply phishing-resistant multifactor authentication (MFA). Log RDP login attempts. Disable command-line and scripting activities and permissions [ CPG 2.N]. Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts [ CPG 4.C]. Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege (PoLP) [ CPG 2.E]. Reduce the threat of credential compromise via the following: Place domain admin accounts in the protected users’ group to prevent caching of password hashes locally. Refrain from storing plaintext credentials in scripts. Implement time-based access for accounts at the admin level and higher [ CPG 2.A, 2.E]. In addition, the authoring authorities of this CSA recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques, and to reduce the impact and risk of compromise by ransomware or data extortion actors: Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (i.e., hard drive, storage device, or the cloud). Maintain offline backups of data and regularly maintain backup and restoration (daily or weekly at minimum). By instituting this practice, an organization limits the severity of disruption to its business practices [ CPG 2.R]. Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with NIST's standards for developing and managing password policies. Use longer passwords consisting of at least 15 characters and no more than 64 characters in length [ CPG 2.B]. Store passwords in hashed format using industry-recognized password managers. Add password user “salts” to shared login credentials. Avoid reusing passwords [ CPG 2.C]. Implement multiple failed login attempt account lockouts [ CPG 2.G]. Disable password “hints.” Refrain from requiring password changes more frequently than once per year. Note: NIST guidance suggests favoring longer passwords instead of requiring regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher. Require administrator credentials to install software. Require phishing-resistant multifactor authentication (MFA) for all services to the extent possible, particularly for webmail, virtual private networks (VPNs), and accounts that access critical systems [ CPG 2.H]. Segment networks to prevent the spread of ransomware. Network segmentation can help prevent the spread of ransomware by controlling traffic flows between—and access to—various subnetworks and by restricting adversary lateral movement [ CPG 2.F]. Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting the ransomware, implement a tool that logs and reports all network traffic and activity, including lateral movement, on a network. Endpoint detection and response (EDR) tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host [ CPG 3.A]. Install, regularly update, and enable real time detection for antivirus software on all hosts. Disable unused ports and protocols [ CPG 2.V]. Consider adding an email banner to emails received from outside your organization [ CPG 2.M]. Disable hyperlinks in received emails. Ensure all backup data is encrypted, immutable (i.e., ensure backup data cannot be altered or deleted), and covers the entire organization’s data infrastructure [ CPG 2.K, 2.L, 2.R]. VALIDATE SECURITY CONTROLS In addition to applying mitigations, the FBI, CISA, and MS-ISAC recommend exercising, testing, and validating your organization's security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. The FBI, CISA, and MS-ISAC recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory. To get started: Select an ATT&CK technique described in this advisory (see Tables 4-16). Align your security technologies against the technique. Test your technologies against the technique. Analyze your detection and prevention technologies’ performance. Repeat the process for all security technologies to obtain a set of comprehensive performance data. Tune your security program, including people, processes, and technologies, based on the data generated by this process. The FBI, CISA, and MS-ISAC recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory. RESOURCES Stopransomware.gov is a whole-of-government approach that gives one central location for ransomware resources and alerts. Resource to mitigate a ransomware attack: CISA, NSA, FBI, and Multi-State Information Sharing and Analysis Center’s (MS-ISAC) Joint #StopRansomware Guide. SLTT organizations are encouraged to implement MS-ISAC’s Ransomware Defense-in-Depth guidance. No-cost cyber hygiene services: Cyber Hygiene Services and Ransomware Readiness Assessment. CISA: Known Exploited Vulnerabilities Catalog CISA, MITRE: Best Practices for MITRE ATT&CK Mapping CISA: Decider Tool CISA: Cross-Sector Cybersecurity Performance Goals CISA: Secure by Design CISA: Implementing Phishing-Resistant MFA CISA: Guide to Securing Remote Access Software REFERENCES [1] Privacy Affairs: “Moral” 8Base Ransomware Targets 2 New Victims [2] VMware: 8base ransomware: A Heavy Hitting Player [3] Infosecurity Magazine: Phobos Ransomware Family Expands With New FAUST Variant [4] The Record: Hospitals offline across Romania following ransomware attack on IT platform [5] Comparitech: What is Phobos Ransomware & How to Protect Against It? [6] Cisco Talos: Understanding the Phobos affiliate structure and activity [7] Cisco Talos: A deep dive into Phobos ransomware, recently deployed by 8Base group [8] Malwarebytes Labs: A deep dive into Phobos ransomware [9] Any Run: Smokeloader [10] Malpedia: Smokeloader [11] Truesec: A case of the FAUST Ransomware [12] VirusTotal: Phobos Domain #1 [13] VirusTotal: Phobos executable: Ahpdate.exe [14] VirusTotal: Phobos GUI extension: ELF File [15] VirusTotal: Phobos IP address: 185.202.0[.]111 [16] VirusTotal: Phobos GUI extension: Binary File [17] Cisco Talos GitHub: IOCs/2023/11/deep-dive-into-phobos-ransomware.txt at main REPORTING The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, a sample ransom-note, communications with Phobos actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. Additional details requested include: a targeted company point of contact, status and scope of infection, estimated loss, operational impact, transaction IDs, date of infection, date detected, initial attack vector, and host and network-based indicators. The FBI and CISA do not encourage paying ransom as payment does not guarantee victim files will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Regardless of whether you or your organization have decided to pay the ransom, the FBI and CISA urge you to promptly report ransomware incidents to the FBI Internet Crime Complaint Center (IC3), a local FBI Field Office, or to CISA at report@cisa.gov or (888) 282-0870. DISCLAIMER The FBI does not conduct its investigative activities or base attribution solely on activities protected by the First Amendment. Your company has no obligation to respond or provide information back to the FBI in response to this engagement. If, after reviewing the information, your company decides to provide referral information to the FBI, it must do so in a manner consistent with federal law. The FBI does not request or expect your company to take any particular action regarding this information other than holding it in confidence due to its sensitive nature. The information in this report is being provided “as is” for informational purposes only. The FBI and CISA not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise does not constitute or imply endorsement, recommendation, or favoring by CISA, the FBI, and the MS-ISAC. ACKNOWLEDGEMENTS The California Joint Regional Intelligence Center (JRIC, CA) and Israel National Cyber Directorate (INCD) contributed to this CSA. VERSION HISTORY February 29, 2024: Initial version.

Today, CISA, the Federal Bureau of Investigation (FBI), and the Multi-State Information Sharing and Analysis Center (MS-ISAC) released a joint Cybersecurity Advisory (CSA), #StopRansomware: Phobos Ransomware, to disseminate known tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs), which are from incident response investigations tied to Phobos ransomware activity from as recently as February, 2024. Structured as a ransomware as a service (RaaS) model, Phobos ransomware actors have targeted entities including municipal and county governments, emergency services, education, public healthcare, and critical infrastructure to successfully ransom several million in U.S. dollars. CISA, the FBI, and MS-ISAC encourage critical infrastructure organizations review and implement the mitigations provided in the joint CSA to reduce the likelihood and impact of Phobos ransomware and other ransomware incidents. For more information, see CISA’s #StopRansomware webpage and the updated #StopRansomware Guide.

CISA released two Industrial Control Systems (ICS) advisories on February 29, 2024. These advisories provide timely information about current security issues, vulnerabilities, and exploits surrounding ICS. ICSA-24-060-01 Delta Electronics CNCSoft-B ICSMA-24-060-01 MicroDicom DICOM Viewer CISA encourages users and administrators to review the newly released ICS advisories for technical details and mitigations.

SUMMARY The Cybersecurity and Infrastructure Security Agency (CISA) and the following partners (hereafter referred to as the authoring organizations) are releasing this joint Cybersecurity Advisory to warn that cyber threat actors are exploiting previously identified vulnerabilities in Ivanti Connect Secure and Ivanti Policy Secure gateways. CISA and authoring organizations appreciate the cooperation of Volexity, Ivanti, Mandiant and other industry partners in the development of this advisory and ongoing incident response activities. Authoring organizations: Federal Bureau of Investigation (FBI) Multi-State Information Sharing & Analysis Center (MS-ISAC) Australian Signals Directorate’s Australian Cyber Security Centre (ASD’s ACSC) United Kingdom National Cyber Security Centre (NCSC-UK) Canadian Centre for Cyber Security (Cyber Centre), a part of the Communications Security Establishment New Zealand National Cyber Security Centre (NCSC-NZ) CERT-New Zealand (CERT NZ) Of particular concern, the authoring organizations and industry partners have determined that cyber threat actors are able to deceive Ivanti’s internal and external Integrity Checker Tool (ICT), resulting in a failure to detect compromise. Cyber threat actors are actively exploiting multiple previously identified vulnerabilities— CVE-2023-46805, CVE-2024-21887, and CVE-2024-21893—affecting Ivanti Connect Secure and Ivanti Policy Secure gateways. The vulnerabilities impact all supported versions (9.x and 22.x) and can be used in a chain of exploits to enable malicious cyber threat actors to bypass authentication, craft malicious requests, and execute arbitrary commands with elevated privileges. During multiple incident response engagements associated with this activity, CISA identified that Ivanti’s internal and previous external ICT failed to detect compromise. In addition, CISA has conducted independent research in a lab environment validating that the Ivanti ICT is not sufficient to detect compromise and that a cyber threat actor may be able to gain root-level persistence despite issuing factory resets. The authoring organizations encourage network defenders to (1) assume that user and service account credentials stored within the affected Ivanti VPN appliances are likely compromised, (2) hunt for malicious activity on their networks using the detection methods and indicators of compromise (IOCs) within this advisory, (3) run Ivanti’s most recent external ICT, and (4) apply available patching guidance provided by Ivanti as version updates become available. If a potential compromise is detected, organizations should collect and analyze logs and artifacts for malicious activity and apply the incident response recommendations within this advisory. Based upon the authoring organizations’ observations during incident response activities and available industry reporting, as supplemented by CISA’s research findings, the authoring organizations recommend that the safest course of action for network defenders is to assume a sophisticated threat actor may deploy rootkit level persistence on a device that has been reset and lay dormant for an arbitrary amount of time. For example, as outlined in PRC State-Sponsored Actors Compromise and Maintain Persistent Access to U.S. Critical Infrastructure), sophisticated actors may remain silent on compromised networks for long periods. The authoring organizations strongly urge all organizations to consider the significant risk of adversary access to, and persistence on, Ivanti Connect Secure and Ivanti Policy Secure gateways when determining whether to continue operating these devices in an enterprise environment. Note: On February 9, 2024, CISA issued Emergency Directive (ED) 24-01: Mitigate Ivanti Connect Secure and Ivanti Policy Secure Vulnerabilities, which requires emergency action from Federal Civilian Executive Branch (FCEB) agencies to perform specific actions on affected products. The Canadian Centre for Cyber Security also issued an alert, Ivanti Connect Secure and Ivanti Policy Secure gateways zero-day vulnerabilities, which provides periodic updates for IT professionals and managers affected by the Ivanti vulnerabilities. Download the PDF version of this report: Threat Actors Exploit Multiple Vulnerabilities in Ivanti Connect Secure and Policy Secure Gateways (PDF, 2.20 MB ) For a downloadable copy of IOCs, see: AA24-060B STIX XML (XML, 70.12 KB ) AA24-060B STIX JSON (JSON, 53.65 KB ) TECHNICAL DETAILS This advisory uses the MITRE ATT&CK ® for Enterprise framework, version 14. See the MITRE ATT&CK Tactics and Techniques in Appendix C for a table of the threat actors’ activity mapped to MITRE ATT&CK tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool. Overview On January 10, 2024, Volexity reported on two vulnerabilities in Ivanti Connect Secure and Ivanti Policy Secure gateways observed being chained to achieve unauthenticated remote code execution (RCE):[ 1] CVE 2023-46805 CVE-2024-21887 Volexity first identified active exploitation in early December 2023, when they detected suspicious lateral movement [ TA0008] on the network of one of their network security monitoring service customers. Volexity identified that threat actors exploited the vulnerabilities to implant web shells, including GLASSTOKEN and GIFTEDVISITOR, on internal and external-facing web servers [ T1505.003]. Once successfully deployed, these web shells are used to execute commands on compromised devices.[ 1] After Ivanti provided initial mitigation guidance in early January, threat actors developed a way to bypass those mitigations to deploy BUSHWALK, LIGHTWIRE, and CHAINLINE web shell variants.[ 2] Following the actors’ developments, Ivanti disclosed three additional vulnerabilities: CVE-2024-21893 is a server-side request forgery vulnerability in the SAML component of Ivanti Connect Secure (9.x, 22.x) Ivanti Policy Secure (9.x, 22.x), and Ivanti Neurons for ZTA that allows an attacker to access restricted resources without authentication. CVE-2024-22024 is an XML vulnerability in the SAML component of Ivanti Connect Secure (9.x, 22.x), Ivanti Policy Secure (9.x, 22.x), and ZTA gateways that allows an attacker to access restricted resources without authentication. CVE-2024-21888 is a privilege escalation vulnerability found in the web component of Ivanti Connect Secure and Ivanti Policy Secure. This vulnerability allows threat actors to gain elevated privileges to that of an administrator. Observed Threat Actor Activity CISA has responded to multiple incidents related to the above vulnerabilities in Ivanti Connect Secure and Policy Secure Gateways. In these incidents, actors exploited these CVEs for initial access to implant web shells and to harvest credentials stored on the devices. Post-compromise, the actors moved laterally into domain environments and have been observed leveraging tools that are native to the Ivanti appliances—such as freerdp, ssh, telnet, and nmap libraries—to expand their access to the domain environment. The result, in some cases, was a full domain compromise. During incident response investigations, CISA identified that Ivanti’s internal and external ICT failed to detect compromise. The organizations leveraged the integrity checker to identify file mismatches in Ivanti devices; however, CISA incident response analysis confirmed that both the internal and external versions of the ICT were not reliable due to the existence of web shells found on systems that had no file mismatches according to the ICTs. Additionally, forensic analysis showed evidence the actors were able to clean up their efforts by overwriting files, time-stomping files, and re-mounting the runtime partition to return the appliance to a “clean state.” This reinforces that ICT scans are not reliable to indicate previous compromise and can result in a false sense of security that the device is free of compromise. As detailed in Appendix A, CISA conducted independent research in a lab environment validating that the ICT is likely insufficient for detecting compromise and that a cyber threat actor may be able to maintain root level persistence despite issuing factory resets and appliance upgrades. INDICATORS OF COMPROMISE See Tables 1 – 4 in Appendix B for IOCs related to cyber actors exploiting multiple CVEs related to Ivanti appliances. For additional indicators of compromise, see: Volexity: Active Exploitation of Two Zero-Day Vulnerabilities in Ivanti Connect Secure VPN Mandiant: Cutting Edge: Suspected APT Targets Ivanti Connect Secure VPN in New Zero-Day Exploitation Mandiant: Cutting Edge, Part 2: Investigating Ivanti Connect Secure VPN Zero-Day Exploitation Mandiant: Cutting Edge, Part 3: Investigating Ivanti Connect Secure VPN Exploitation and Persistence Attempts Memory and disk forensics were used during forensic analysis, combined with the Integrity Checker Tool, to identify malicious files on the compromised Ivanti Connect Secure VPN appliance. This advisory provides a list of combined authoring organization IOCs and open source files identified by Volexity via network analysis. Disclaimer : Some IP addresses in this advisory may be associated with legitimate activity. Organizations are encouraged to investigate the activity around these IP addresses prior to taking action such as blocking. Activity should not be attributed as malicious without analytical evidence to support it is used at the direction of, or controlled by, threat actors. DETECTION METHODS YARA Rules See Appendix D for additional open source YARA rules, provided by Volexity, that may aid network defenders in detecting malicious activity within Ivanti Connect Secure VPN appliances. For more information on detection methods, visit Mandiant’s blog post Cutting Edge, Part 2: Investigating Ivanti Connect Secure VPN Zero-Day Exploitation or the Volexity GitHub page. INCIDENT RESPONSE The authoring organizations encourage you to assess your organization’s user interface (UI) software and systems for evidence of compromise and to hunt for malicious activity using signatures outlined within this advisory. If compromise is suspected or detected, organizations should assume that threat actors hold full administrative access and can perform all tasks associated with the Ivanti Connect Secure VPN appliance as well as executing arbitrary code and installing malicious payloads. Note: These are vendor-managed appliances and systems may be encrypted with limited access. Thus, collecting artifacts may be limited on some versions of appliances. The authoring organizations recommend investigating associated devices on the network to identify lateral movement in the absence of access to the Secure Connect appliance. If a potential compromise is detected, organizations should: Quarantine or take offline potentially affected hosts. Reimage compromised hosts. Reset all credentials that may have been exposed during the compromise, including user and service accounts. Identify Ivanti hosts with Active Directory (AD) access, threat actors can trivially export active domain administrator credentials during initial compromise. Until there is evidence to the contrary, it is assumed that AD access on compromised systems is connected to external authentication systems such as Lightweight Directory Access Protocol (LDAP) and AD. Collect and review artifacts such as running processes/services, unusual authentications, and recent network connections. Note: Removing malicious administrator accounts may not fully mitigate risk considering threat actors may have established additional persistence mechanisms. Report the compromise to FBI Internet Crime Complaint Center (IC3) at IC3.gov, local FBI field Office, or CISA via the agency’s Incident Reporting System or its 24/7 Operations Center ( report@cisa.gov or 888-282-0870). State, local, tribal, or territorial government entities can also report to MS-ISAC ( SOC@cisecurity.org or 866-787-4722). Organizations outside of the United States should contact their national cyber center. (See the Reporting section.) MITIGATIONS These mitigations apply to all critical infrastructure organizations and network defenders using Ivanti Connect Secure VPN and Ivanti Policy Secure. The authoring organizations recommend that software manufacturers incorporate Secure by Design principles and tactics into their software development practices. These principles and tactics can limit the impact of exploitation—such as threat actors leveraging newly discovered, unpatched vulnerabilities within Ivanti appliances—thus, strengthening the secure posture for their customers. For more information on secure by design, see CISA’s Secure by Design webpage and joint guide . The authoring organizations recommend organizations implement the mitigations below to improve your cybersecurity posture based on threat actor activity and to reduce the risk of compromise associated with Ivanti vulnerabilities. These mitigations align with the cross-sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, techniques, and procedures. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections. As organizations make risk decisions in choosing a VPN, to include decisions regarding continued operation of Ivanti Connect Secure and Policy Secure gateways, avoid VPN solutions that use proprietary protocols or non-standard features. VPNs as a class of devices carry some specific risks that a non-expert implementer may trigger (e.g., authentication integration and patching). When choosing a VPN, organizations should consider vendors who: Provide a Software Bill of Materials (SBOM) to proactively identify, and enable remediation of, embedded software vulnerabilities, such as deprecated operating systems. Allow a restore from trusted media to establish a root of trust. If the software validation tooling can be modified by the software itself, there is no way to establish a root of trust other than returning the device to the manufacturer (return material authorization [RMA]). Are a CVE Numbering Authority (CNA) so that CVEs are assigned to emerging vulnerabilities in a timely manner. Have a public Vulnerability Disclosure Policy (VDP) to enable security researchers to proactively share and disclose vulnerabilities through coordinated vulnerability disclosure (CVD). Have in place a clear end-of-life policy (EoL) to prepare customers for updating to supported product versions. Limit outbound internet connections from SSL VPN appliances to restrict access to required services. This will limit the ability of an actor to download tools or malware onto the device or establish outbound connections to command and control (C2) servers. Ensure SSL VPN appliances configured with Active Directory or LDAP authentication use low privilege accounts for the LDAP bind. Limit SSL VPN connections to unprivileged accounts only to help limit the exposure of privileged account credentials. Keep all operating systems, software, and firmware up to date. Timely patching is one of the most efficient and cost-effective steps an organization can take to minimize its exposure to cybersecurity threats. Organizations should patch vulnerable software and hardware systems within 24 to 48 hours of vulnerability disclosure. Prioritize patching known exploited vulnerabilities in internet-facing systems [ CPG 1.E]. Secure remote access tools. Implement application controls to manage and control execution of software, including allowlisting remote access programs. Application controls should prevent installation and execution of portable versions of unauthorized remote access and other software. A properly configured application allowlisting solution will block any unlisted application execution. Allowlisting is important because antivirus solutions may fail to detect the execution of malicious portable executables when the files use any combination of compression, encryption, or obfuscation. Strictly limit the use of Remote Desktop Protocols (RDP) and other remote desktop services. If RDP is necessary, rigorously apply best practices, for example [ CPG 2.W]: Audit the network for systems using RDP. Close unused RDP ports. Enforce account lockouts after a specified number of attempts. Apply phishing-resistant multifactor authentication (MFA). Log RDP login attempts. Configure the Windows Registry to require User Account Control (UAC) approval for any PsExec operations requiring administrator privileges to reduce the risk of lateral movement by PsExec. Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (e.g., hard drive, storage device, or the cloud). Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with NIST's standards for developing and managing password policies. Use longer passwords consisting of at least 15 characters [ CPG 2.B]. Store passwords in hashed format using industry-recognized password managers. Add password user “salts” to shared login credentials. Avoid reusing passwords [ CPG 2.C]. Implement multiple failed login attempt account lockouts [ CPG 2.G]. Disable password “hints.” Require administrator credentials to install software. Review the CISA and NSA joint guidance for Selecting and Hardening Remote Access VPN Solutions. VALIDATE SECURITY CONTROLS In addition to applying mitigations, the authoring organizations recommend exercising, testing, and validating your organization's security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. The authoring organizations recommend testing your existing security controls inventory to assess how the controls perform against the ATT&CK techniques described in this advisory. To get started: Select an ATT&CK technique described in this advisory (Appendix C). Align your security technologies against the technique. Test your technologies against the technique. Analyze your detection and prevention technologies’ performance. Repeat the process for all security technologies to obtain a set of comprehensive performance data. Tune your security program, including people, processes, and technologies, based on the data generated by this process. The authoring organizations recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory. REPORTING U.S. organizations should report every potential cyber incident to the U.S. government. When available, each report submitted should include the date, time, location, type of activity, number of people, and type of equipment used for the activity, the name of the submitting company or organization, and a designated point of contact. Reports can be submitted to the FBI’s Internet Crime Complaint Center (IC3), local FBI Field Office, or CISA via the agency’s Incident Reporting System or its 24/7 Operations Center at report@cisa.gov or (888) 282-0870. The FBI encourages organizations to report information concerning suspicious or criminal activity to their local FBI Field Office. Australian organizations that have been impacted or require assistance regarding Ivanti compromise, contact ASD’s ACSC via 1300 CYBER1 (1300 292 371), or by submitting a report to cyber.gov.au. UK organizations that have been impacted by Ivanti compromise, should report the incident to the National Cyber Security Centre. Organizations outside of the United States or Australia should contact their national cyber center. REFERENCES Active Exploitation of Two Zero-Day Vulnerabilities in Ivanti Connect Secure VPN | Volexity Ivanti Connect Secure VPN Exploitation Goes Global | Volexity KB CVE-2023-46805 (Authentication Bypass) & CVE-2024-21887 (Command Injection) for Ivanti Connect Secure and Ivanti Policy Secure Gateways Cutting Edge, Part 2: Investigating Ivanti Connect Secure VPN Zero-Day Exploitation | Mandiant DISCLAIMER The information in this report is being provided “as is” for informational purposes only. CISA and authoring organizations do not endorse any commercial entity, product, company, or service, including any entities, products, or services linked within this document. Any reference to specific commercial entities, products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by CISA and authoring organizations. ACKNOWLEDGEMENTS Volexity, Mandiant, and Ivanti contributed to this advisory. VERSION HISTORY February 29, 2024: Initial version. APPENDIX A: CISA’S PRODUCT EVALUATION FINDINGS Research Approach As part of ongoing efforts to effectively serve the cybersecurity community with actionable insights and guidance, CISA conducted research by using a free and downloadable version of the Ivanti Connect Secure virtual appliance to assess potential attack paths and adversary persistence mechanisms. The virtual appliances were not connected to the internet, and were deployed in a closed virtualized network, with a non-internet connected Active Directory. This research included a variety of tests on version 22.3R1 Build 1647, connected to Active Directory credentials, to leverage the access obtained through CVE-2023-46805, CVE-2024-21887 and CVE-2024-21893. Put simply, CISA’s research team wanted to answer the question: “How far could an attacker go if they set were to exploit these CVEs remotely?” Persistent Post-Reset and -Upgrade Access Leveraging these vulnerabilities, CISA researchers were able to exfiltrate domain administrator cleartext credentials [ TA0006], gain root-level persistence [ TA0003], and bypass integrity checks used by the Integrity Checker application. CISA’s Incident Response team observed these specific techniques leveraged during the agency’s incident response engagements, along with the native tools and libraries to conduct internal reconnaissance and compromise domains behind the Ivanti appliances. CISA researchers assess that threat actors are able to use the credentials to move deeper into the environment. The ability to exfiltrate domain administrator cleartext credentials, if saved when adding an “Active Directory Authentication server” during setup, was accomplished by using the root-level access obtained from the vulnerabilities to interface directly with the internal server and retrieve the cached credentials as shown in Figure 4, APPENDIX A. Users who currently have active sessions to the appliance could have their base64 encoded active directory cleartext passwords, in addition to the New Technology LAN Manager (NTLM) password hashes, retrieved with the same access, as shown in Figure 10, APPENDIX A. In addition to users with active sessions, users previously authenticated can have base64 encoded active directory plaintext passwords and NTLM hashes harvested from the backups of the data.mdb database files stored on the appliance, as shown in Figure 15 and 16, APPENDIX A. The root-level access allows adversaries to maintain persistence despite issuing factory resets and appliance upgrades while deceiving the provided integrity checkers, creating the illusion of a clean installation. Due to the persistence mechanism being stored on the encrypted partition of the drive and inaccurate integrity check results, it is untenable for network administrators to validate their application has not been compromised without also decrypting the partition and validating against a clean installation of the appliance, which are actions not easily accomplished at present. Without major alterations of the integrity checking process, it is conceivable that new vulnerabilities that afford root-level access to the appliance could also result in root-kit level persistence to the appliance. Below is proof of concept being released by CISA, which demonstrates the capacity of and opportunity for a threat actor to exfiltrate Domain Administrator credentials that were used during appliance configuration: Below is a demonstration of the capacity for post exploitation exfiltration of base64 encoded cleartext credentials for active directory users and their associated NTLM password hashes: APPENDIX B: INDICATORS OF COMPROMISE Table 1: Ivanti Connect Secure VPN Indicators of Compromise Filename Description Purpose /home/perl/DSLogConfig.pm Modified Perl module. Designed to execute sessionserver.pl. /usr/bin/a.sh gcore.in core dump script. /bin/netmon Sliver binary. /home/venv3/lib/python3.6/site-packages/*.egg Python package containing WIREFIRE among other files. /home/etc/sql/dsserver/sessionserver.pl Perl script to remount the filesystem with read/write access. Make sessionserver.sh executable, execute it, then restore original mount settings. /home/etc/sql/dsserver/sessionserver.sh Script executed by sessionserver.pl. Uses regular expressions to modify compcheckresult.cgi to insert a web shell into it; also creates a series of entries into files associated with the In-build Integrity Checker Tool to evade detection when periodic scans are run. /home/webserver/htdocs/dana-na/auth/compcheckresult.cgi Modified legitimate component of the ICS VPN appliance, with new Perl module imports added and a one-liner to execute commands based on request parameters. Allows remote code execution over the Internet if the attacker can craft a request with the correct parameters. /home/webserver/htdocs/dana-na/auth/lastauthserverused.js Modified legitimate JavaScript component loaded by user login page of the Web SSL VPN component of Ivanti Connect Secure. Modified to harvest entered credentials and send them to a remote URL on an attacker-controlled domain. Table 2: Ivanti Connect Secure VPN Indicators of Compromise Value Type Description 88.119.169[.]227 IP Address 103.13.28[.]40 IP Address 46.8.68[.]100 IPv4 206.189.208[.]156 IP Address DigitalOcean IP address tied to UTA0178. gpoaccess[.]com Hostname Suspected UTA0178 domain discovered via domain registration patterns. webb-institute[.]com Hostname Suspected UTA0178 domain discovered via domain registration patterns. symantke[.]com Hostname UTA0178 domain used to collect credentials from compromised devices. 75.145.243[.]85 IP Address UTA0178 IP address observed interacting with compromised device. 47.207.9[.]89 IP Address UTA0178 IP address observed interacting with compromised device tied to Cyberoam proxy network. 98.160.48[.]170 IP Address UTA0178 IP address observed interacting with compromised device tied to Cyberoam proxy network. 173.220.106[.]166 IP Address UTA0178 IP address observed interacting with compromised device tied to Cyberoam proxy network. 73.128.178[.]221 IP Address UTA0178 IP address observed interacting with compromised device tied to Cyberoam proxy network. 50.243.177[.]161 IP Address UTA0178 IP address observed interacting with compromised device tied to Cyberoam proxy network. 50.213.208[.]89 IP Address UTA0178 IP address observed interacting with compromised device tied to Cyberoam proxy network. 64.24.179[.]210 IP Address UTA0178 IP address observed interacting with compromised device tied to Cyberoam proxy network. 75.145.224[.]109 IP Address UTA0178 IP address observed interacting with compromised device tied to Cyberoam proxy network. 50.215.39[.]49 IP Address UTA0178 IP address observed interacting with compromised device tied to Cyberoam proxy network. 71.127.149[.]194 UTA0178 IP address observed interacting with compromised device tied to Cyberoam proxy network. 173.53.43[.]7 UTA0178 IP address observed interacting with compromised device tied to Cyberoam proxy network. Table 3: Host-Based Indicators (HBIs) Indicators of Compromise Filename Hash Value Description Cav-0.1-py3.6.egg ed4b855941d6d7e07aacf016a2402c4c870876a050a4a547af194f5a9b47945f WIREFIRE web shell Health.py 3045f5b3d355a9ab26ab6f44cc831a83 CHAINLINE web shell compcheckresult.cgi 3d97f55a03ceb4f71671aa2ecf5b24e9 CHAINLINE web shell lastauthserverused.js 2ec505088b942c234f39a37188e80d7a LIGHTWIRE web shell lastauthserverused.js 8eb042da6ba683ef1bae460af103cc44 WARPWIRE credential harvester variant lastauthserverused.js a739bd4c2b9f3679f43579711448786f WARPWIRE credential harvester variant lastauthserverused.js a81813f70151a022ea1065b7f4d6b5ab WARPWIRE credential harvester variant lastauthserverused.js d0c7a334a4d9dcd3c6335ae13bee59ea WARPWIRE credential harvester variant lastauthserverused.js e8489983d73ed30a4240a14b1f161254 WARPWIRE credential harvester variant logo.gif N/A — varies Configuration and cache dump or CAV web server log exfiltration login.gif N/A — varies Configuration and cache dump [a-fA-f0-9]{10\.css N/A — varies Configuration and cache dump visits.py N/A — varies WIREFIRE web shell Table 4: Host-Based Indicators (HBIs) Indicators of Compromise Network Indicator Type Description symantke[.]com Domain WARPWIRE C2 server miltonhouse[.]nl Domain WARPWIRE variant C2 server entraide-internationale[.]fr Domain WARPWIRE variant C2 server api.d-n-s[.]name Domain WARPWIRE variant C2 server cpanel.netbar[.]org Domain WARPWIRE variant C2 server clickcom[.]click Domain WARPWIRE variant C2 server clicko[.]click Domain WARPWIRE variant C2 server duorhytm[.]fun Domain WARPWIRE variant C2 server line-api[.]com Domain WARPWIRE variant C2 server areekaweb[.]com Domain WARPWIRE variant C2 server ehangmun[.]com Domain WARPWIRE variant C2 server secure-cama[.]com Domain WARPWIRE variant C2 server 146.0.228[.]66 IPv4 WARPWIRE variant C2 server 159.65.130[.]146 IPv4 WARPWIRE variant C2 server 8.137.112[.]245 IPv4 WARPWIRE variant C2 server 91.92.254[.]14 IPv4 WARPWIRE variant C2 server 186.179.39[.]235 IPv4 Mass exploitation activity 50.215.39[.]49 IPv4 Post-exploitation activity 45.61.136[.]14 IPv4 Post-exploitation activity 173.220.106[.]166 IPv4 Post-exploitation activity APPENDIX C: M ITRE ATT&CK TACTICS AND TECHNIQUES Table 5: Cyber Actors ATT&CK Techniques for Enterprise Initial Access Technique Title ID Use Exploit Public-Facing Applications T1190 Cyber actors will use custom web shells planted on public facing applications which allows persistence in victims’ environment. Persistence Technique Title ID Use Valid Accounts T1078 Cyber actors leverage compromised accounts to laterally move within internal systems via RDP, SBD, and SSH. Server Software Component: Web Shell T1505.003 Cyber actors may use web shells on internal- and external-facing web servers to establish persistent access to systems. Execution Technique Title ID Use Command and Scripting Interpreter: PowerShell T1059.001 Cyber actors leverage code execution from request parameters that are decoded from hex to base64 decoded, then passed to Assembly.Load(). Which is used to execute arbitrary powershell commands. Exploitation for Client Execution T1203 Cyber actors will exploit software vulnerabilities such as command-injection and achieve unauthenticated remote code execution (RCE). APPENDIX D: DETECTION METHODS rule apt_webshell_pl_complyshell: UTA0178 { meta: author = "threatintel@volexity.com" date = "2023-12-13" description = "Detection for the COMPLYSHELL webshell." hash1 = "8bc8f4da98ee05c9d403d2cb76097818de0b524d90bea8ed846615e42cb031d2" os = "linux" os_arch = "all" report = "TIB-20231215" scan_context = "file,memory" last_modified = "2024-01-09T10:05Z" license = "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt" rule_id = 9995 version = 4 strings: $s = "eval{my $c=Crypt::RC4->new(" condition: $s } rule apt_webshell_aspx_glasstoken: UTA0178 { meta: author = "threatintel@volexity.com" date = "2023-12-12" description = "Detection for a custom webshell seen on external facing server. The webshell contains two functions, the first is to act as a Tunnel, using code borrowed from reGeorg, the second is custom code to execute arbitrary .NET code." hash1 = "26cbb54b1feb75fe008e36285334d747428f80aacdb57badf294e597f3e9430d" os = "win" os_arch = "all" report = "TIB-20231215" scan_context = "file,memory" last_modified = "2024-01-09T10:08Z" license = "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt" rule_id = 9994 version = 5 strings: $s1 = "=Convert.FromBase64String(System.Text.Encoding.Default.GetString(" ascii $re = /Assembly\.Load\(errors\)\.CreateInstance\("[a-z0-9A-Z]{4,12}"\).GetHashCode\(\);/ condition: for any i in (0..#s1): ( $re in (@s1[i]..@s1[i]+512) ) } rule webshell_aspx_regeorg { meta: author = "threatintel@volexity.com" date = "2018-08-29" description = "Detects the reGeorg webshell based on common strings in the webshell. May also detect other webshells which borrow code from ReGeorg." hash = "9d901f1a494ffa98d967ee6ee30a46402c12a807ce425d5f51252eb69941d988" os = "win" os_arch = "all" reference = "https://github.com/L-codes/Neo-reGeorg/blob/master/templates/tunnel.aspx" report = "TIB-20231215" scan_context = "file,memory" last_modified = "2024-01-09T10:04Z" license = "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt" rule_id = 410 version = 7 strings: $a1 = "every office needs a tool like Georg" ascii $a2 = "cmd = Request.QueryString.Get(\"cmd\")" ascii $a3 = "exKak.Message" ascii $proxy1 = "if (rkey != \"Content-Length\" && rkey != \"Transfer-Encoding\")" $proxy_b1 = "StreamReader repBody = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(\"UTF-8\"));" ascii $proxy_b2 = "string rbody = repBody.ReadToEnd();" ascii $proxy_b3 = "Response.AddHeader(\"Content-Length\", rbody.Length.ToString());" ascii condition: any of ($a*) or $proxy1 or all of ($proxy_b*) } rule hacktool_py_pysoxy { meta: author = "threatintel@volexity.com" date = "2024-01-09" description = "SOCKS5 proxy tool used to relay connections." hash1 = "e192932d834292478c9b1032543c53edfc2b252fdf7e27e4c438f4b249544eeb" os = "all" os_arch = "all" reference = "https://github.com/MisterDaneel/pysoxy/blob/master/pysoxy.py" report = "TIB-20240109" scan_context = "file,memory" last_modified = "2024-01-09T13:45Z" license = "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt" rule_id = 10065 version = 3 strings: $s1 = "proxy_loop" ascii $s2 = "connect_to_dst" ascii $s3 = "request_client" ascii $s4 = "subnegotiation_client" ascii $s5 = "bind_port" ascii condition: all of them } rule apt_webshell_py_categorical: UTA0178 { meta: author = "threatintel@volexity.com" date = "2024-01-18" description = "Detection for the CATEGORICAL webshell." os = "linux" os_arch = "all" scan_context = "file,memory" severity = "critical" strings: $s1 = "exec(zlib.decompress(aes.decrypt(base64.b64decode" ascii $s2 = "globals()[dskey].pop('result',None)" ascii $s3 = "dsid=request.cookies.get('DSID'" ascii condition: any of ($s*) }