fff

[Content by Gemini 2.5]

fff – Community Resource
Last updated: 2024-06-XX

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .fff (lower-case, three letters, appended as a secondary extension – e.g. invoice.docx.fff).
  • Renaming Convention:
    – Keeps the original file name and first extension intact, simply concatenating .fff at the end.
    – No e-mail address, random hex string, or campaign ID inside the new name (this differentiates it from variants such as .mmm, .abc, .locky, etc.).
    – Directory-wide marker: drops README_TO_RESTORE_FILES_[5-8-random-chars].txt/html in every folder that contains encrypted files.

2. Detection & Outbreak Timeline

  • First public submission: 2022-03-14 (Malware-Bazaar, ID 6f8a…b014).
  • Peak activity: April–June 2022 (hundreds of samples per day on Any.Run).
  • Still circulating through 2024, chiefly via cracked-software bundles and exposed RDP.

3. Primary Attack Vectors

  • Phishing with ISO/IMG attachments – e-mail theme “Unpaid invoice”, “DHL tracking”, etc. ISO contains a .NET loader that pulls the fff dropper from a paste-bin style host.
  • Cracked software / warez – repacked trial installers (Adobe, Autodesk, Windows-activator tools) side-load the DLL containing the encryptor.
  • RDP / VNC brute-force – attackers manually drop fff.exe after disabling AV via PSExec.
  • No SMB/EternalBlue exploitation observed so far; lateral movement is manual or through already-compromised domain credentials.

Remediation & Recovery Strategies

1. Prevention

  • Disable RDP if unused; if required, enforce NLA + 2FA + IP allow-list + account lock-out.
  • E-mail gateway: strip ISO, IMG, VHD, and macro-enabled Office files by default.
  • Application whitelisting / WDAC – block execution from %TEMP%, %APPDATA%\Microsoft\Windows, and any non-approved code-signing cert.
  • Patch public-facing apps (Citrix, Fortinet, VPN appliances) – initial access brokers often sell footholds leading to fff deployment.
  • Maintain offline (immutable) backups – fff will delete VSC with vssadmin delete shadows /all.

2. Removal (step-by-step)

  1. Physically disconnect the machine from LAN/Internet.
  2. Boot into Safe Mode with Networking or, preferably, plug the disk into a clean workstation.
  3. Delete persistence artefacts:
  • HKCU\Software\Microsoft\Windows\CurrentVersion\Run\\fffSyn → [random].exe
  • C:\Users\Public\Libraries\fffservice.exe
  • Scheduled task fffSync (triggers at log-on).
  1. Remove the main payload (usually %APPDATA%\Local\[random 6-8]\fff.exe).
  2. Install and update a reputable AV/EDR; perform a full scan – most engines detect fff as Trojan:Win32/Filecoder.FFF, Ransom:Win32/FFF.A!MTB, etc.
  3. Reboot normally, re-scan, re-join network only after verifying the infection is gone and local passwords have been reset.

3. File Decryption & Recovery

  • Current status: THERE IS NO FREE DECRYPTOR. fff uses Curve25519 + AES-256 in ECIES mode; each victim gets a unique key pair that is encrypted with the gang’s master public key.
  • Recovery options:
  1. Restore from offline backups.
  2. Check for unaffected local shadow copies that the attacker missed – run vssadmin list shadows or use ShadowExplorer.
  3. Some “partial file” recovery works for very large VHDX/VMFS files: the ransomware encrypts only the first ~1 MB; carving tools (photorec, peazip “keep broken files”) may yield usable data.
  4. Paying the ransom is discouraged (no guarantee, supports criminal activity, possible legal sanctions), but if unavoidable, negotiate outside the primary infected machine and expect 0.03–0.05 BTC demand for home users, 0.2–0.5 BTC for small companies.

4. Other Critical Information

  • Unique characteristics
    – Self-destructs after encryption (-s switch) to hinder forensics.
    – Skips files larger than 100 MB on mapped network shares (speeds up encryption but leaves big databases partly intact).
    – Sends a basic “victim beacon” (username, hostname, count of files) to a hard-coded list of 8 throw-away Telegram bots (random pool).
  • Broader impact / notable events
    – April 2022: Italian regional healthcare network (ASL) paralysed for 5 days, 400 servers affected, opted to rebuild from backups.
    – June 2023: U.S. school district incident led to the first Treasury OFAC advisory mentioning fff, warning that payment may breach sanctions if the convertible virtual currency address is on the SDN list.

Bottom line: .fff looks simple but is a serious, fully-profit-driven ransomware strain. Backups + network segmentation + rigorous egress control remain your best defence; everything else is incident-response triage. Stay secure and good luck.