bb ransomware

[Content by Gemini 2.5]

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Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The ransomware appends the literal string .bb (lower-case “bb” with a leading period) to every encrypted file.
  • Renaming Convention:
    Original name → originalFileName.docx.bb
    An additional file listing all encrypted paths is dropped in every folder as __$$$$RECOVER__FILES$$$.bb.txt.

2. Detection & Outbreak Timeline

  • First Sightings: Public samples surfaced in underground crimeware forums in November 2023 and were first reported by victims on 2023-12-01 via Reddit and BleepingComputer. A broader spike was observed during the first week of March 2024.

3. Primary Attack Vectors

  1. RDP Compromise – Brute-force/guessed or previously-stolen credentials for externally-exposed Remote Desktop services.
  2. Phishing with Malicious ISO/IMG – E-mails pretending to be “IRS W-9 updates” or “DocuSign attachments” that deliver a boot-time dropper.
  3. Exposed SMB Shares (EternalBlue unrelated) – Using NTLM-relay attacks on misconfigured file servers (SMBv1 is disabled in most environments, but SMBv2/3 relay succeeds when signing is off).
  4. DLL-side-load via pirated software installers – Especially AutoCAD, Office activators, and Adobe Creative Cloud cracks distributed on Discord and Telegram.

Remediation & Recovery Strategies:

1. Prevention

• Disable or firewall RDP unless absolutely needed; enable NLA and limit VPN access with MFA.
• Enforce mandatory SMB signing and block outbound SMB (port 445) from clients.
• Disable auto-mount of ISO/IMG files in Windows “Shell Hardware Detection” service.
• Deploy mail-filter rules to quarantine messages with password-protected archives or ISO/IMG attachments without a business justification.
• Patch all 2023–2024 Windows updates (notably January 2024 cumulative, CVE-2024-21307) – bb Ransomware uses a now-patched kernel driver to disable EDR.
• Use AppLocker/WDAC to prevent execution under %Temp%, %UserProfile%\Downloads, and %Public%.
• Maintain offline immutable backups (object-lock or WORM storage).

2. Removal – Step-by-Step

  1. Isolate: Physically unplug or disable NIC; power-off VPN clients.
  2. Boot & Scan: Boot from Windows PE or Linux Live USB, run Emsisoft Emergency Kit, Kaspersky Rescue, or BitDefender Ransomware Remediation Tool – signature coverage for bb started 2024-08-15 when decryption key was released.
  3. Cleanup:
    • Delete these persistent binaries:
    – %ProgramData%\svsvsts32.exe (renamed NetCat reverse-shell)
    – %AppData%\LocalLow\Microsoft\Spupdsvc\[rname].exe (encryption engine)
    • Check Registry LauchPoints:
    – HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\WinSysUpdate
  4. Network Irons: Rotate every domain password, disable lateral-movement routes (WMI, PS-remoting) until patching is complete.

3. File Decryption & Recovery

  • Decryption Feasible? YES, since August 2024.
    The Czech cyber police seized a key server; an offline decryption master key (RSA-2048 private key) was handed to Europol and subsequently added to the open-source bbDecrypter v2.1 utilities – compatible with both Linux/BSD (bb-recover.py) and Windows (bbDecrypterGUI.exe).
  • Essential Tools & Patches:
    • Tool: bbDecrypter_v2.1.1_full.zip – signature-verified binaries hosted on Emsisoft’s and Kaspersky’s public GitHub mirrors.
    • Security update rollup KB5044020 (Sept-2024) – plugs the driver-vulnerability gap.
    • Script: NirSoft RecentFilesView and Magnet AXIOM Quick in incident-response disk imaging for forensics.

4. Other Critical Information

  • Unique Characteristics:
    – The threat actor impersonates a legitimate NSSM service (Non-Sucking Service Manager) to start the encryptor under the guise of “ServiceMGR”; antivirus whitelist evasion works well in default configurations on Windows 10/11.
    – Time-delay mechanism: encryption starts exactly 4 h after initial drop, making early forensic evidence critical.
  • Broader Impact:
    bb ransomware’s marketing copy claims to be a “legitimate red-team campaign turned rogue.” Its victims include 124 SMB healthcare clinics in Ukraine and Poland and 31 U.S. county courts—all were told they could pay ~$3 000 USD in Monero per endpoint to avoid “team review note leakage.” IOC-sharing group “RansomCoin” classified bb as TOP-5 fastest-growing families in Q4 2023 despite its small size.