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In the ever-evolving landscape of cyber threats, ransomware continues to pose a significant risk to organizations worldwide. Among the numerous groups orchestrating these disruptive attacks, BlackMatter emerged in mid-2021 as a potent and concerning player. Operating under the Ransomware-as-a-Service (RaaS) model, BlackMatter quickly gained notoriety for its technical sophistication, aggressive targeting – including critical infrastructure sectors – and its suspected links to previously dismantled high-profile ransomware operations like DarkSide.
First observed in July 2021, BlackMatter represented more than just a new ransomware variant; it signaled the resilience and adaptability of cybercriminal enterprises. Despite its relatively short operational window before announcing its shutdown in November 2021, the group inflicted considerable damage and demonstrated advanced Tactics, Techniques, and Procedures (TTPs). This article serves as a technical deep dive for security professionals, analyzing the origins, operational methodologies, victimology, and defensive strategies related to the BlackMatter ransomware group, offering insights to better combat similar persistent threats.
Origins & Evolution
BlackMatter surfaced in the cyber threat landscape in July 2021, shortly after the widely publicized shutdowns of the DarkSide and REvil (Sodinokibi) ransomware operations following major attacks like the Colonial Pipeline incident. This timing, coupled with significant overlaps in TTPs, infrastructure, and even operational policies, led multiple cybersecurity agencies and researchers (including CISA, the FBI, and NSA) to suspect BlackMatter was a direct rebrand or successor to the DarkSide RaaS platform. Some analysts also suggested potential overlaps or shared membership with elements of the REvil group, citing technical clues found in preceding REvil attacks.
BlackMatter operators actively advertised their RaaS program on prominent Russian-language cybercrime forums like Exploit and XSS, a notable move as many such forums had ostensibly banned ransomware advertisements after the Colonial Pipeline fallout. They sought affiliates, particularly initial access brokers (IABs), offering substantial payments (reportedly up to $100,000) for verified access to corporate networks meeting specific criteria – typically organizations with revenues exceeding $100 million USD and networks ranging from 500 to 15,000 hosts. To establish credibility, the BlackMatter group reportedly deposited a significant sum (around 4 BTC) into an escrow account on a forum as proof of funds.
Operationally, BlackMatter demonstrated evolution by developing ransomware payloads for both Windows and Linux environments, including specific capabilities to target VMware ESXi servers and Network Attached Storage (NAS) devices – critical components of modern enterprise infrastructure. They claimed their ransomware incorporated the "best features" of DarkSide and REvil.
However, the group's reign was short-lived. Around early November 2021, BlackMatter abruptly announced it was shutting down operations, citing "pressure from the authorities" and the unavailability of key team members. This followed increased international law enforcement focus and potential disruptions targeting ransomware infrastructure. While the group officially ceased operations under the BlackMatter name, the cybersecurity community remains watchful. The cyclical nature of ransomware suggests that the skilled actors behind BlackMatter likely haven't disappeared entirely but may have dispersed, joined other RaaS operations (like Conti, which was active at the time), or are potentially regrouping for a future re-emergence under a different banner, much like the suspected evolution from DarkSide to BlackMatter itself. The emergence of the BlackCat/ALPHV ransomware shortly after BlackMatter's shutdown fueled speculation about potential connections, embodying the "Hydra effect" often seen in the ransomware ecosystem.
Tactics & Techniques
BlackMatter operated as a sophisticated RaaS platform, providing its affiliates with the tools and infrastructure needed to conduct attacks. Their modus operandi involved a multi-stage approach, leveraging a combination of common and advanced TTPs to infiltrate networks, escalate privileges, deploy ransomware, and extort victims.
1. Initial Access: BlackMatter affiliates primarily gained initial access by:
Exploiting Compromised Credentials: Leveraging previously stolen or weak administrator/user credentials for services like Remote Desktop Protocol (RDP), Virtual Private Networks (VPNs), or other exposed interfaces. The lack of Multi-Factor Authentication (MFA) was often a key enabler.
Using Legitimate Software: Utilizing legitimate remote monitoring and management (RMM) software or remote desktop tools (often setting up trial accounts) to establish a foothold and maintain persistence.
Partnering with IABs: Purchasing access from Initial Access Brokers who specialize in breaching networks.
Exploiting Vulnerabilities: Targeting known vulnerabilities in internet-facing devices and software.
2. Execution & Persistence: Once inside, BlackMatter employed various techniques:
Custom Payloads: Deploying compact (~80kb) ransomware binaries written in C, often tailored with victim-specific configurations.
Native APIs & WMI: Using legitimate Windows APIs (kernel32.dll, ntdll.dll) for core functions and Windows Management Instrumentation (WMI) for tasks like discovering and later deleting volume shadow copies (
SELECT * FROM Win32_ShadowCopy).Registry Run Keys: Establishing persistence using
RunOnceregistry keys (HKCU\...\RunOnce,HKLM\...\RunOnce). Check out the Windows registry.Safe Mode Execution: The Windows variant supported execution in Safe Mode, potentially bypassing some security controls.
3. Privilege Escalation: To gain higher privileges, BlackMatter utilized:
UAC Bypass: Exploiting known User Account Control bypass techniques, such as the CMSTPLUA COM interface or the ICMLuaUtil COM method (affecting Windows 7 through 10).
Process Injection: Injecting malicious code into legitimate processes like
svchost.exeto run with SYSTEM privileges.Access Token Manipulation: Stealing access tokens from processes like
explorer.exeto impersonate users.
4. Defense Evasion: BlackMatter was notable for its emphasis on evading defenses:
Obfuscation: Employing techniques like ROT13 encoding for module names and Base64 encoding for configurations. Resolving API functions by hash to hinder static analysis. Learn about CyberChef.
Anti-Debugging/Sandbox Evasion: Incorporating checks to detect debuggers or virtualized environments.
Impairing Defenses: Attempting to stop or disable security software services.
Deleting Shadow Copies: Using WMI or COM objects (
wbemcomn.dll) to delete volume shadow copies (vssadmin delete shadows /all /quiet), hindering file recovery.Modifying Permissions: Using
icaclsto grant 'Everyone' full control over target drives (icacls "<DriveLetter>:\*" /grant Everyone:F /T /C /Q), ensuring files could be encrypted.Registry Modification: Deleting proxy settings and modifying the desktop wallpaper registry key to display the ransom note.
5. Credential Access:
LSASS Memory Dumping: Harvesting credentials stored in the Local Security Authority Subsystem Service (LSASS) process memory, potentially using tools facilitated by procmon-like drivers or known techniques.
6. Discovery: Extensive reconnaissance within the network was key:
Active Directory Enumeration: Using Lightweight Directory Access Protocol (LDAP) queries to discover hosts, users, and network structure.
Network Share Discovery: Leveraging the Server Message Block (SMB) protocol and functions like
srvsvc.NetShareEnumAllto find accessible network shares (including ADMIN$, C$, SYSVOL, NETLOGON).System Information: Gathering OS version, architecture, username, domain name, disk sizes, and the system's
MachineGuid(used as the victim ID).Process and Service Discovery: Enumerating running processes (
NtQuerySystemInformation) and services (EnumServicesStatusExW).
7. Lateral Movement:
SMB/Admin Shares: Using discovered credentials to connect to administrative shares on other machines via SMB and remotely executing tasks or encrypting data.
8. Command and Control (C2):
Encrypted Communication: Using HTTPS for C2 communication, with data encrypted using AES.
Beaconing: Sending system information (machine name, OS, user, domain, disk sizes) back to the C2 server.
Specific User-Agents: Impersonating common browser user-agents (
Firefox/89.0,Edge/91.0.864.37, etc.).
9. Exfiltration:
Double Extortion: Before encryption, BlackMatter affiliates attempted to exfiltrate sensitive data, often over web services or the C2 channel (HTTP POST), threatening to leak it on their dedicated TOR-based leak site if the ransom wasn't paid.
10. Impact:
Data Encryption: Encrypting files using a combination of Salsa20 (for file content) and RSA-1024 (to encrypt the Salsa20 key). Encrypted files were appended with a unique 9-character alphanumeric extension.
Ransom Note: Dropping a ransom note named
[extension].README.txtin directories and on the desktop, providing instructions and a link to the TOR payment portal.Targeting Specific Systems: Including payloads specifically designed to encrypt Linux systems, VMware ESXi virtual machines, and NAS devices.
Backup Destruction: Notably, BlackMatter often attempted to wipe or reformat backup data stores and appliances rather than just encrypting them, making recovery much harder.
Wallpaper Change: Modifying the desktop wallpaper to display a ransom message.
MITRE ATT&CK TTPs Mapping:
The following table summarizes some of the key TTPs employed by BlackMatter, mapped to the MITRE ATT&CK framework:
|
Tactic
|
Technique ID
|
Technique Name
|
|---|---|---|
|
Initial Access
|
T1078
|
Valid Accounts
|
|
Initial Access
|
T1133
|
External Remote Services
|
|
Execution
|
T1059.001
|
Command and Scripting Interpreter: PowerShell
|
|
Execution
|
T1059.003
|
Command and Scripting Interpreter: Windows Command Shell
|
|
Execution
|
T1047
|
Windows Management Instrumentation
|
|
Execution
|
T1106
|
Native API
|
|
Persistence
|
T1547.001
|
Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder
|
|
Privilege Escalation
|
T1055
|
Process Injection
|
|
Privilege Escalation
|
T1134.001
|
Access Token Manipulation: Token Impersonation/Theft
|
|
Privilege Escalation
|
T1548.002
|
Abuse Elevation Control Mechanism: Bypass User Account Control
|
|
Defense Evasion
|
T1027
|
Obfuscated Files or Information
|
|
Defense Evasion
|
T1112
|
Modify Registry
|
|
Defense Evasion
|
T1140
|
Deobfuscate/Decode Files or Information
|
|
Defense Evasion
|
T1222.001
|
File and Directory Permissions Modification: Windows Permissions
|
|
Defense Evasion
|
T1497
|
Virtualization/Sandbox Evasion
|
|
Defense Evasion
|
T1562.001
|
Impair Defenses: Disable or Modify Tools
|
|
Credential Access
|
T1003.001
|
OS Credential Dumping: LSASS Memory
|
|
Discovery
|
T1007
|
System Service Discovery
|
|
Discovery
|
T1012
|
Query Registry
|
|
Discovery
|
T1016
|
System Network Configuration Discovery
|
|
Discovery
|
T1018
|
Remote System Discovery
|
|
Discovery
|
T1057
|
Process Discovery
|
|
Discovery
|
T1082
|
System Information Discovery
|
|
Discovery
|
T1083
|
File and Directory Discovery
|
|
Discovery
|
T1135
|
Network Share Discovery
|
|
Lateral Movement
|
T1021.002
|
Remote Services: SMB/Windows Admin Shares
|
|
Command and Control
|
T1071.001
|
Application Layer Protocol: Web Protocols
|
|
Command and Control
|
T1573.001
|
Encrypted Channel: Symmetric Cryptography
|
|
Exfiltration
|
T1041
|
Exfiltration Over C2 Channel
|
|
Exfiltration
|
T1567
|
Exfiltration Over Web Service
|
|
Impact
|
T1486
|
Data Encrypted for Impact
|
|
Impact
|
T1489
|
Service Stop
|
|
Impact
|
T1490
|
Inhibit System Recovery (Shadow Copy Deletion)
|
|
Impact
|
T1561
|
Disk Wipe (Targeting Backups)
|
Targets or Victimology
BlackMatter's targeting strategy appeared multi-faceted, driven primarily by financial gain. While the group publicly advertised specific criteria for its affiliates (organizations with >$100M annual revenue, 500-15,000 hosts), the reality of attacks often reflects opportunistic exploitation of vulnerabilities combined with these aspirational goals.
Key Targeting Aspects:
Financial Threshold: The stated preference for high-revenue companies aimed to maximize potential ransom payouts, with demands reportedly ranging from $80,000 to $15 million USD, payable in Bitcoin or Monero.
Critical Infrastructure: Despite public claims of avoiding certain sectors, a joint advisory from CISA, FBI, and NSA confirmed that BlackMatter successfully compromised multiple U.S. critical infrastructure entities, including at least two organizations in the Food and Agriculture sector. This demonstrated a willingness, or perhaps an inability of affiliates to strictly adhere to the group's stated policies, to impact essential services.
Stated Exclusions (Potential Misdirection): BlackMatter publicly listed sectors they supposedly forbade affiliates from targeting, including healthcare, critical infrastructure (power grids, nuclear facilities), oil and gas, defense industry, non-profits, and government agencies. This mirrored policies previously stated by DarkSide and could have been an attempt at public relations management or avoiding intense law enforcement scrutiny, though their actions contradicted these claims.
Geographic Focus: The group primarily targeted organizations in English-speaking countries, with the US, UK, Canada, and Australia frequently mentioned.
Industry Breadth: Beyond critical infrastructure, attacks spanned various sectors as affiliates found vulnerable targets, potentially including technology, finance, education, and manufacturing, aligning with the broad scope often seen in RaaS operations.
Technical Targets: Specific focus was placed on compromising virtualization infrastructure (VMware ESXi) and NAS devices, recognizing their importance for data storage and business continuity.
Insider Threat Recruitment: The offer of a $100,000 bounty for initial network access explicitly targeted potential insider threats, indicating another vector for initiating attacks.
Potential Impact:
Operational Disruption: Encryption of critical systems, including ESXi servers and NAS devices, could halt business operations entirely.
Data Breach and Extortion: The double extortion tactic meant victims faced not only system unavailability but also the public release or sale of sensitive stolen data if the ransom was unpaid.
Financial Loss: Significant costs associated with ransom payments (if made), recovery efforts, incident response, legal fees, and reputational damage.
Supply Chain Effects: Attacks on critical infrastructure or major suppliers could have cascading effects on consumers and dependent businesses.
Attack Campaigns
Given BlackMatter's relatively brief operational period (July-November 2021), distinct, large-scale named campaigns are less documented compared to longer-lived groups. However, their activity during this time was significant and characterized by several key patterns:
Critical Infrastructure Targeting (Summer/Fall 2021): The most notable aspect of BlackMatter's activity was its confirmed targeting of U.S. critical infrastructure, specifically within the Food and Agriculture sector, as highlighted by the CISA/FBI/NSA joint advisory (AA21-287A) released in October 2021. These attacks underscored the real-world risks posed by the group.
Consistent Double Extortion: Across its observed attacks, BlackMatter affiliates consistently employed the double extortion model. Data exfiltration was a standard procedure before deploying the ransomware, with threats to publish stolen data on their TOR-based leak site used as leverage.
Leveraging Initial Access Brokers (IABs): BlackMatter actively recruited and utilized IABs, suggesting many of their intrusions likely originated from access purchased on dark web markets rather than solely through affiliate-driven exploitation efforts.
Focus on ESXi and Linux: Reports indicated a deliberate effort to target and encrypt VMware ESXi environments and other Linux-based systems, recognizing their prevalence in enterprise networks and the significant disruption caused by their compromise.
Rapid Deployment Post-Access: Once initial access was gained and sufficient internal reconnaissance was completed, the ransomware deployment phase, including encryption and backup wiping, often proceeded quickly to maximize impact before detection and response.
While specific victim names beyond the generalized critical infrastructure alerts were often not publicly disclosed, the group's leak site did list victims who presumably refused to pay the ransom, showcasing their successes and applying pressure to current and future targets. The overall campaign demonstrated a financially motivated operation capable of executing sophisticated attacks against valuable targets.
Defenses
Defending against threats like BlackMatter, and the ransomware ecosystem in general, requires a multi-layered, defense-in-depth strategy. While BlackMatter itself is no longer active under that name, the TTPs persist. Security professionals should focus on hardening systems, limiting attack surfaces, enabling detection, and preparing for response. One crucial aspect is security logging.
Key Detection & Protection Strategies:
Strong Authentication and Access Control:
Enforce MFA: Mandate Multi-Factor Authentication for all remote access (VPN, RDP), cloud services, email, and critical system logins. This is one of the most effective defenses against credential compromise.
Strong, Unique Passwords: Implement and enforce strong password policies. Prohibit password reuse across accounts and services. Use Privileged Access Management (PAM) solutions.
Least Privilege: Ensure users and service accounts have only the minimum permissions necessary to perform their roles.
Just-in-Time (JIT) Access: Implement time-based access for administrative accounts, disabling them when not actively needed.
Patch and Vulnerability Management:
Timely Patching: Maintain a rigorous patch management program for operating systems, applications, firmware, and especially internet-facing systems and appliances (VPNs, firewalls, etc.). Follow a Patch Management Strategy.
Vulnerability Scanning: Regularly scan internal and external assets for vulnerabilities and prioritize remediation.
Network Security and Segmentation:
Network Segmentation: Segment networks to limit the blast radius of a potential ransomware infection. Prevent lateral movement between segments unless strictly necessary.
Firewall Rules: Implement strict firewall rules, including host-based firewalls, to control traffic flow, especially SMB (port 445) communication.
Limit Administrative Shares: Disable or restrict access to administrative shares (ADMIN$, C$) where possible. If required, limit access to specific administrative hosts and monitor heavily.
Endpoint and Server Security:
Endpoint Detection & Response (EDR): Deploy and properly configure EDR solutions capable of behavior-based detection to identify malicious activity indicative of ransomware (e.g., mass file encryption, shadow copy deletion attempts, LSASS access).
Antivirus/Anti-Malware: Keep signatures and engines up-to-date. Enable tamper protection features.
Disable Unnecessary Services: Harden systems by disabling unused ports and services.
Scripting Control: Disable or constrain command-line and scripting environments (like PowerShell) for standard users.
Data Backup and Recovery:
Regular Backups: Implement a robust backup strategy (e.g., 3-2-1 rule: three copies, two different media, one offsite).
Offline and Immutable Backups: Ensure backups are stored offline or are immutable (cannot be altered or deleted by ransomware). Air-gapped backups provide the strongest protection.
Test Restorations: Regularly test backup restoration procedures to ensure they work correctly and meet recovery time objectives (RTO).
Encrypt Backups: Protect backup data with encryption.
Credential Protection:
LSASS Hardening: Disable the storage of clear text passwords in LSASS memory. Consider Credential Guard (Windows 10/Server 2016+) or Protected Process Light (PPL) for LSASS.
Limit NTLM/WDigest: Disable or restrict the use of older authentication protocols like NTLM and WDigest where feasible.
Audit Kerberos Activity: Monitor Domain Controllers for anomalous Kerberos ticket-granting activity (potential Kerberoasting). Learn What is Kerberos.
Monitoring and Incident Response:
Centralized Logging & SIEM: Aggregate logs from endpoints, servers, network devices, and applications into a SIEM. Develop detection rules specifically targeting ransomware TTPs (e.g., WMI usage for shadow copy deletion, suspicious SMB activity, LSASS access attempts).
Network Traffic Analysis: Monitor network traffic for unusual patterns, C2 communication, and large data outflows (exfiltration). Implement detection signatures (like the Snort rules provided by CISA for BlackMatter).
Incident Response Plan: Develop, maintain, and regularly practice an incident response plan specifically for ransomware attacks. Ensure roles and responsibilities are clear. Immediate isolation of suspected infected systems is critical. Take a look at cyber incident response plan.
Threat Intelligence: Stay informed about current ransomware threats, TTPs, and Indicators of Compromise (IOCs).
User Awareness Training:
Educate users about phishing, social engineering, and safe browsing habits. Train them on how to report suspicious activity.
By implementing these layered defenses, organizations can significantly reduce their risk of falling victim to ransomware groups employing tactics similar to BlackMatter.
Conclusion
BlackMatter ransomware, though operational for only a few months in 2021, served as a stark reminder of the persistent and evolving nature of cybercriminal enterprises. Likely emerging from the ashes of the DarkSide operation, it exemplified the RaaS model's efficiency, targeting critical infrastructure and employing sophisticated TTPs for infiltration, evasion, and impact, including data exfiltration and backup destruction. Its abrupt shutdown under alleged law enforcement pressure highlights the potential impact of coordinated disruption efforts, yet the underlying threat actors and techniques likely persist, potentially resurfacing under new guises. For security professionals, the legacy of BlackMatter underscores the critical importance of robust, layered defenses – emphasizing MFA, rigorous patching, network segmentation, immutable backups, vigilant monitoring, and well-practiced incident response plans – to combat the enduring ransomware threat. It is also important to have What is Threat Intelligence.
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Arun KL
Arun KL is a cybersecurity professional with 15+ years of experience in IT infrastructure, cloud security, vulnerability management, Penetration Testing, security operations, and incident response. He is adept at designing and implementing robust security solutions to safeguard systems and data. Arun holds multiple industry certifications including CCNA, CCNA Security, RHCE, CEH, and AWS Security.
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