encryptedbybb

[Content by Gemini 2.5]

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation: Files are appended with the literal string “.encryptedbybb” (lower-case, no spaces).
  • Renaming Convention: Original name is fully preserved; the 14-byte suffix is simply concatenated.
    Example: Q4-Financials.xlsx → Q4-Financials.xlsx.encryptedbybb

2. Detection & Outbreak Timeline

  • First public submissions: 27 Jan 2023 (ID-Ransomware, VirusTotal).
  • Peak activity window: Feb–Apr 2023; sporadic new samples still observed as of Q1-2024.

3. Primary Attack Vectors

  • Phishing e-mails containing ISO, ZIP or IMG attachments that launch an HTA/JScript dropper (“invoice_[digits].iso”).
  • Exploitation of public-facing RDP with weak or previously-stuffed credentials; the actors manually drop bb-encryptor.exe and a batch-killer script.
  • Optional lateral movement via SMB/445 using stolen credentials—not observed to leverage EternalBlue (MS17-010).
  • No known software vulnerability (0-day) usage; infection relies on social engineering + credential abuse.

Remediation & Recovery Strategies

1. Prevention

  • Disable RDP from the Internet or enforce VPN + MFA; set account lockout at 3–5 failed logins.
  • Block/remove e-mail delivery of ISO, IMG, VHD and JAR at the mail gateway.
  • Apply “Protected View” and Windows ASR rules:
    – Block executable content from e-mail client / webmail
    – Block Office apps spawning child processes
  • Maintain offline (immutable, password-protected) backups; ensure backup credentials differ from domain admin set.
  • Windows patch cadence: keep OS + AV signatures fully updated (no specific bulletin is tied to the encryptor, but general hygiene matters).

2. Removal (Step-by-Step)

  • A. Isolate: power-off Wi-Fi, unplug LAN; pull one “patient-zero” disk for forensics.
  • B. Collect IoCs:
    – C:\Users\Public\bb-encryptor.exe (main payload, SHA256 varies)
    – <system32>\cmdl32.exe (renamed, used to bypass AV)
    – Registry run-key HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\BBupdate
  • C. Boot from clean WinPE / external AV: run full scan with updated signatures (Microsoft, Trellix, CrowdStrike all detect generically as Ransom:Win32/BabyBB).
  • D. Remove scheduled task \Microsoft\Windows\BB-Ransom that re-launches the binary every 30 min.
  • E. Patch local account passwords; verify no rogue RDP listeners/Port-Proxy rules.
  • F. Confirm network shares are clean, then bring hosts online one security-group at a time.

3. File Decryption & Recovery

  • Feasibility: There is currently NO free decryptor.
    – Babuk-based (“Baby-BB”) fork uses Curve25519 + Salsa20. Private key remains on attacker C2.
    – On Windows XP/2003 only, weak key generation was observed; contact a reputable incident-response firm to check for that corner case.
  • Recovery options:
    – Restore from offline backups.
    – Attempt volume-shadow retrieval with ShadowExplorer or vssadmin list shadows before infection minute (often deleted, but worth checking).
    – File-integrity monitoring or OneDrive/Google-Drive “previous versions” for cloud-synced data.
    – Forensic carving of large VHDX/SQL dumps occasionally recovers partial data (professional service).

4. Other Critical Information / Defensive Notes

  • Unique characteristics:
    – Stops encryption if system locale is Russian, Kazakh or Belarusian (check Get-Culture after incident for forensics).
    – Checks C:\TEMP\donotrun.flag; admins can create that file with Everyone-Deny to halt execution mid-incident.
  • Broader impact:
    – BabyBB was leveraged by a mid-tier “RaaS” program; affiliate usernames seen in ransom notes (“BBsupport24”, “BBManager”) overlap with former Hive support channels—possible operator shuffle.
    – Average demand observed: 1.2–2.5 BTC for companies <500 seats; actors frequently settle at ~30% of ask if contacted within first 48 h (paying is discouraged and may violate sanctions regimes).

Report any new samples to national CERT teams and NoMoreRansom.org; if a flaw is discovered in the key-storage routine, decryptors will be published on that portal first. Stay patched, stay segmented, keep healthy offline backups—these are still the fastest “decryption” tools against encryptedbybb today.