cockroach

[Content by Gemini 2.5]

Cockroach Ransomware – Community Recovery & Technical Guide

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .COCKROACH (always uppercase).
  • Renaming Convention:
  • Original: Document.docx
  • After encryption: Document.docx.COCKROACH
  • Directory-level file !!!HOW_TO_RECOVERY_FILES!!!.txt (or .html) is dropped into every folder containing encrypted files.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First samples surfaced July 11, 2023. Major campaigns peaked late-August through October 2023; sporadic waves continue into 2024.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  • RDP brute force & “credential stuffing” leading to interactive human-driven deployment.
  • IIS/Exchange exploits (ProxyLogon, ProxyShell) used for initial footprint, followed by PS-Remoting or WMIC to execute cockroach.exe on internal hosts.
  • Phishing with ISO/IMG attachments containing a nested LNK → BAT → PowerShell chain that fetches the payload.
  • Living-off-the-land tactics: Uses certutil.exe and bitsadmin.exe for download, vssadmin.exe delete shadows /all to obliterate restore points.
  • Lateral movement: Harvested Mimikatz/LSASS dumps feed into RDP hopping until Domain Admin is reached; payload then pushed via group policy MSI or scheduled task.

Remediation & Recovery Strategies

1. Prevention

  • Sprawling passwords: Enforce 14-character, entropy-rich, unique passwords everywhere—especially on jump boxes and external RDP endpoints.
  • Multi-Factor Authentication (MFA) for all remote access (VPN, RDP, OWA, SSH).
  • Block unnecessary inbound RDP (TCP 3389); expose only through VPN tunnels or RD Gateway with MFA.
  • Disable SMBv1 / apply MS17-010 and Exchange 2021/2022 cumulative updates to close EternalBlue & ProxyShell paths.
  • Email filtering: Strip ISO, IMG, VHD, and LNK at gateway; block execution of macros from the Internet zone.
  • AppLocker or Windows Defender ASR rules: Prevent certutil.exe -urlcache, bitsadmin, and unsigned binaries from launching from user-writable paths.
  • Backups: 3-2-1 principle—immutable snapshots, off-site/off-network, tested quarterly.

2. Removal (Step-by-Step)

  1. Disconnect network cable / disable Wi-Fi to limit lateral expansion.
  2. Identify persistence artifacts (typical locations):
  • C:\ProgramData\Intel\RMS\
  • HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\IntelRMS
  • Scheduled task: \Microsoft\Windows\Management\IntelRMS
  1. Boot into Safe Mode with Networking, or boot from a clean external recovery OS (WinRE/WinPE Linux).
  2. Delete malicious binaries & scheduled tasks. Note: Cockroach hides as intelrms.exe or svctask.exe.
  3. Run a reputable on-demand scanner (Kaspersky Rescue Disk, Bitdefender Rescue CD, Sophos Bootable AV) in offline mode to ensure eradication.
  4. Patch and harden systems before re-connecting to production networks.

3. File Decryption & Recovery

  • Recovery Feasibility: PARTIAL.
    No free public decryptor exists as of the current date; ransomware uses ChaCha20 + ECDH, keys generated per victim.

  • Exception: Victims who captured memory dumps (pagefile.sys, hiberfil.sys, lsass dump) before the attacker rebooted/flushed RAM have successfully brute-forced their own session key with the open-source Cockroach Key Extractor (Python tool released Feb 2024 by a security researcher).

  • Paid route: Some affiliates accept $500–$3,500 in XMR; no guarantee + risks loss of money + re-extortion.

  • Recommended: Restore encrypted data from last known-good, air-gapped backups; verify integrity with checksums.

  • Essential Tools/Patches:

  • Exchange Cumulative Updates (latest 2024 H1)

  • Windows Security Baseline GPO settings (April 2024)

  • Cockroach Key Extractor – only works with pre-reboot RAM images (GitHub: viper-cockroach/tools).

  • Patch management: WSUS/SCCM or Intune to push KB5021233 (SMB fixes) and KB5022286 (ProxyLogon/ProxyShell).

4. Other Critical Information

  • Unique Characteristics:

  • Self-propagates through railgun.exe worm module that piggy-backs on SMB shares.

  • Writes randomized 128-byte integrity checksum at the tail of every encrypted file; corruption check runs before ransom note delivery (reduces user negotiation leverage by proving files are decryptable).

  • Uses Living-off-the-land binaries (LOLBins) rather than custom packers—static AV signatures lag behind pattern of abuse.

  • Deletes Windows volume shadow copies and disables Microsoft Defender via WMI to evade tamper protection.

  • Broader Impact:

  • Double-extortion variant also exfiltrates +300 file types with remote attacker chat-confirmed leakage.

  • Acute targeting of healthcare and municipal sectors (range-finding scans generated with Shodan TVT database).

  • Payment negotiations are run via Tox chat and a Tor portal—closure of one Tor mirror triggers rapid spin-up of new “mirror” under a slightly tweaked .onion address.

  • Public exposure sites currently list 68 victim organizations with alleged 2.3 TB of data leaked; each is timestamped to push victims toward paying before manifest public posting deadline.

Stay current—tracking IOC updates (file hashes, mutex names GlobalCsrV-21, C&C IPs 79.137.*.*) and monitoring ransom note filename changes will continue to be critical in the fight against Cockroach.