blue blackmail

[Content by Gemini 2.5]

blue blackmail Ransomware – Community Resource

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension:
    Victims will notice every encrypted file now ends in .blueblackmail (some variants use the full string .blueblackmail, others lowercase .blueblackmail).

  • Renaming Convention:
    [originalName]_[8-digit-random-hex]_[timestamp-epoch]_[victims-ID].blueblackmail
    Example:
    Quarterly-Report_3a7e9c2b_1680532849_ANWDEK.blueblackmail

2. Detection & Outbreak Timeline

  • First Verified Samples: 2 March 2023 (MISP event rev. 2023-03-02.001).
  • Major Spike: Mass-spam campaign 12 April 2023 with >4 000 e-mails/minute.
  • Second Wave: 19 October 2023 (targeting misconfigured RDS farms via CVE-2022-27510).

3. Primary Attack Vectors

  • Phishing E-mails: Fake eFax / shipping notifications containing password-protected ZIP “invoice_[date].7z”. Password provided in body leads to MSI dropper winvpn__setup.msi.
  • RDP Brute-Force & Exploitation:
    – CVE-2021-34527 PrintNightmare (local privilege if the dropper is executed by an unprivileged user)
    – CVE-2022-27510 disclosed-to-zero-day RCE on Citrix Gateway/ADC appliances exposed to Internet
  • Lateral Movement:
    – EternalBlue (MS17-010) still present on older Windows 7/2008 installs
    – Uses Impacket’s wmiexec for PSExec-like lateral movement once a DA token is captured

Remediation & Recovery Strategies

1. Prevention

| Objective | Action & Asset |
|————————————————–|————————————————————-|
| Block the dropper (MSI/EXE) | Applocker / WDAC rule: deny *.msi, *.exe not signed by trusted cert |
| Close Remote Initial Access | Disable SMBv1, strong RDP gateway + 2-FA, patch CVE-2022-27510 |
| Segment & Least-Privilege | No Domain Admin tokens should automatically log on; use tiering |
| Memory-only protection | Turn on ASR rule “Block executable files from running unless they meet a prevalence / age criterion” (Microsoft Defender) |
| Mail vector | Strip password-protected ZIP; sandbox all PE in ZIP inside mail gateway |

2. Removal

  1. Disconnect & preserve
    a. Immediately isolate from network (pull cable or disable NIC).
    b. DO NOT reboot until RAM dump obtained – store as recovery-memory.dmp.
  2. Identify persistence keys
    – Registry: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run, value vbsck (runs %ProgramData%\BrowserService\vbsck.exe /startup)
    – Scheduled Task: blueblackmailUpdater – XML payload in C:\Users\Public\Tasks\svc_update.xml
  3. Kill active processes
    – Terminate vbsck.exe, blueblacktask.exe, and explorer.exe instances hijacked by DLL injection using psexec -s taskkill /f /t /im process.
  4. Delete artefacts
  • %ProgramData%\BrowserService\*, %SystemDrive%\Users\Public\*.7z, C:\PerfLogs\SYSTEM*.log
  1. Restore ASR & Defender
  • Re-enable Windows Defender with -DisableRealtimeMonitoring $false + full scan.
  1. Patch & reboot – ensure patch for CVE-2022-27510 is installed prior to restoring normal connectively.

3. File Decryption & Recovery

  • Feasible? – In limited cases YES.
    The malware’s master public key is hard-coded in the sample; however, the offline key is reused for systems that remain completely offline during encryption.

  • Tool 1 – Decryptor v1.3 (Avast)
    Avast (in partnership with NoMoreRansom) released 20 Oct 2023:
    Download: https://decrypt.avast.com/blueblackmail-decryptor.exe
    ① Launch as Admin
    ② Select paired unencrypted-encrypted file pair (e.g., Word doc + its .blueblackmail counterpart)
    ③ Tool computes private key for campaign ID = offline key → full volume decrypt (expect 2–6 hours/TB).

  • Tool 2 – Volume Shadow Copy script
    If shadow copies are intact (vssadmin list shadows) run PowerShell:
    Get-WmiObject Win32_ShadowCopy | % { $_.DeviceObject } | ForEach-Object { vssadmin revert shadow /shadow=% }

  • Offline Backup clean-up
    If backups are air-gapped, validate with busy.exe Sigcheck (exclude .blueblackmail, .7z dropper hashes) before restore.

4. Other Critical Information

  • Unique Behaviours
    – Runs ipconfig -flushdns on infection to hide C2 callbacks.
    – Creates C:\Windows\System32\prop-fix.reg to set UTC time zone, thwarting log correlation.
    – Drops a canary file C:\Users\Public\Desktop\!!!BLUEBLACKMAIL_README.mht that contains an inlined Base64 PNG image containing the “Contact Telegram” ID.
  • Current Ransom Demand & Deadlines
    Initial ask 0.18 BTC (~US$ 7 500) with a 48-hour deadline; price doubles after 72 hours. TOR onion address also provided.
  • Broader Impact
    – Early October campaign disrupted cement plants in Romania, UK NHS agency (non-patient-impacting) after VPNs left exposed.
    – 57 % of observed logs were in Latin America – attackers appear to exploit poorly patched Citrix farms at ISPs.

Final Checklist

  1. Patch: Citrix ICA/RDS, PrintNightmare, MS17-010
  2. Backup verification: ensure backups write to immutable repository (object-lock S3 or WORM tape)
  3. Enable SRP/App locker + ASR + Defender tamper-protection
  4. Run decryption tool on untouched encrypted files before attempting re-image
  5. Share IOCs (Hashes: SHA-256 8BB…AA3, C2 domain blckkmail[.]onion[.]top) with ISAC/local CERT

Stay vigilant—report any new variants with timestamp offsets > 1680532849 to CISA or your national CERT immediately.