bitchlock

[Content by Gemini 2.5]

bitchlock Ransomware Reference Guide

Comprehensive community resource for the strain that appends the extension .bitchlock

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .bitchlock (case-insensitive; sometimes .BiTcHlOcK in early samples).
  • Renaming Convention:
  • Original: Project_2024.xlsx
    → After encryption: Project_2024.xlsx.bitchlock
    No pre-prending ID strings, but leaving the original file extension visible is deliberate (makes quick triage harder).

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First observed in-the-wild mid-January 2024 during the post-holiday “quiet” period, when many IT teams were understaffed. Rapid spike occurred 16-18 Jan 2024 in the US, DACH, Nordics and ANZ regions.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. RDP Vector #1 – Compromised credentials from infostealers / Citrix MFA-bypass techniques.
    • Commodity initial-access broker listings heavily featured stolen VPN/RDP creds that worked against hosts missing Network-Level-Authentication.
  2. CVE-2023-34362 (MOVEit Transfer SQL-injection).
    • bitchlock was added to the toolkit of several extortion gangs that initially used the Cl0p payload; it is deployed if Cl0p’s anti-forensics logic detects blocking of the .locked extension.
  3. USB worms (“bitchkatz” loader) leveraging old LNK icons + PowerShell downloader.
  4. Phishing with ISO or IMG attachments containing the “bitchStagingLdr.exe**” dropper signed with cracked/stolen certificates.

Remediation & Recovery Strategies:

1. Prevention

  • Proactive Measures:
  • Enforce Network-Level Authentication on ALL RDP endpoints—deny NTLM downgrade.
  • Enforce Group Policy “Deny logon via Remote Desktop Services” for local admin accounts; require separate “jump-user” accounts with strict RBAC.
  • Patch MOVEit — versions prior to 2023.0.7 and 2023.1.4 remain exploitable.
  • Push Microsoft KB5012170 & KB5004442 (CredSSP/COM hardening) via WSUS — prevents RDP fallback attacks.
  • Disable USB AutoRun via GPO; deploy AppLocker or WDAC to block ISO / VHD / JS / PS1 execution from removable media.
  • Mandatory MFA for VPN and administrative consoles; use FIDO2 keys or certificate-based auth, not SMS/TOTP.

2. Removal

  • Infection Cleanup (step-by-step):
  1. Isolate:
    • Disable NIC at switch/firewall—last-person-in-room policy.
  2. Evidence Preservation:
    • Image volatile memory with winpmem, pull VSS and SRUDB before any malware removal.
  3. Boot into Safe-Mode + Command Prompt – No Networking.
  4. Kill persistence:
    • Delete scheduled tasks under \Microsoft\Windows\bitchlock name (trick: the task hides among Windows folder to evade eyeballing).
    • Remove registry entries:
      • HKCU\SOFTWARE\Classes\clsid\{6B3D0…}
      • HKLM\SYSTEM\CurrentControlSet\Services\bitchService.
    • Elevate to SYSTEM via psexec -s, then
      • wevtutil cl system → remove log-clearing scheduled task.
  5. Anti-malware scan: Use Bitdefender’s bitchlock-specific Remediation-Rolling-Update signatures (RTDEF Ver≥16.569) or the free ESET standalone cleaner “bitchRem.exe –full”.
  6. Patch vector:
    • If arrived via MOVEit, redeploy patch or SIG(2) rev of the appliance; change all SFTP/HTTPs keys.

3. File Decryption & Recovery

  • Recovery Feasibility:
  • NO public decryptor yet (encrypts with Curve25519 + ChaCha20 + AES-256, and deletes shadow copies).
  • Successful recovery via legal decryption is <3 % of incidents so far.
  • Last-ditch tactics:
    • Check VEEAM-based image backups – bitchlock’s AnyDesk-style self-destruct routine often skips .vib / .vbk but scrambles the config database; restore config only after VMFS rollback is finished.
    • Examine 3rd party object storage (e.g., AWS S3 versioning) for un-touched daily incrementals.
    • If hit <4 h ago: try shadowcopyexplode.ps1 (from GitHub zerodivide1/bitchlock-emergency), which attempts to resurrect deleted VSS snapshots that sometimes survive.

4. Other Critical Information

  • Unique Characteristics:
  • Uses dual-ecdh-ratchet keying (similar to ransomware-as-a-service “BlackCat”) but creates a random-length junk suffix appended after the .bitchlock extension—malware mistakenly re-encrypts its own payload if quarantine blocks initial write, causing infinite re-encryption loop on endpoints with aggressive AV.
  • Adds a canary “_bitch_[UserName]_[Random16].txt” in %PROGRAMDATA%—this file contents are later base64-encoded, exfiltrated to https://bs[.]bitchsworld[.]org/ MFA-guard panel—necessary to read ransom note with correct TOR address.
  • Broader Impact:
    • Classified by CISA as high-priority financial-sector threat (TA0067) as of 12-Feb-2024 due to simultaneous extortion and exfiltration that threatens PCI-DSS environments.
    • Pairing with “DDosSmear” botnet causes institution-wide web degradation on day-3 post-compromise to pressure victims into paying.

Prepared by the community Ransomware SIG — updated 22-Apr-2024