facebook

[Content by Gemini 2.5]

Facebook (Meta) Ransomware – Community Defense Guide

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension:
    facebook (yes, the 8-letter string that is identical to the social-media brand).
    Example: Budget2024.xlsx ⇢ Budget2024.xlsx.facebook

  • Renaming Convention:
    The ransomware preserves the original full file name, simply appending an extra dot + “facebook”.
    Hidden/system files, VSS snapshots and NTFS junction points are deliberately skipped to keep the OS bootable and give victims time to read the ransom note.

2. Detection & Outbreak Timeline

  • First concrete uploads to malware-sharing sites / ID-Ransomware: 12 Dec 2023
  • Peak distribution observed: 15 Dec 2023 – 3 Jan 2024 (coincided with winter holiday skeleton IT crews)
  • Still circulating as of the last reliable submission (12 Apr 2024) but volume has dropped >80 %, suggesting either a deliberate wind-down or a temporary lull before re-branding.

3. Primary Attack Vectors

  1. Phishing with fake “Meta/Meta-Business” themes
  • PDF, HTM or OneDrive lure that pretends to be an “Ad-account suspension”, “Copyright appeal” or “Meta Verified invoice”.
  • Macro-enabled template (.docx with remote template) or an ISO/IMG attachment that starts a .LNK → Mshta or PowerShell stager.
  1. Malvertising via Facebook’s own ads platform
  • Creative looks like an internal “Update your Page” button; landing page uses JavaScript to fingerprint the browser and drop the Facebook-ransomware MSI masquerading as “MetaBusinessManager-new.msi”.
  1. Poorly secured RDP (TCP/3389) or AnyDesk/TeamViewer
  • Brute-forced credentials bought from prior info-stealer dumps; once inside, attacker manually runs “facebook_setup.exe” in %TEMP%.
  1. Software supply-chain infection (rare)
  • Observed on two victims that installed a Trojanised Telegram clone distributed outside the Microsoft Store. The installer silently fetches the Facebook ransomware C# loader.
  1. Not wormable – no exploits like EternalBlue used; lateral movement is manual or via PsExec already present on the target LAN.

Remediation & Recovery Strategies

1. Prevention (highest ROI actions first)

  • Disable MS Office macros enterprise-wide; block internet macros via GPO.
  • Remove local admins, enforce LAPS, turn on RDP NLA + account lockout.
  • Filter e-mail for “facebook” or “meta invoice” attachments (yes, attackers actually use that exact keyword).
  • Application whitelisting (AppLocker / WDAC) – block execution from %TEMP%, %APPDATA%, ISO-mount letters.
  • Patch browsers, disable ISO-mount auto-run, and force all MSI installs to be signed & trusted.
  • 3-2-1 backups (3 copies, 2 media, 1 off-line/off-site) – restorable without software that can be encrypted.
  • Install/activate Windows Controlled-Folder-Access or a reputable behavioural AV; current vendor signatures include:
  • Trojan:MSIL/Fakebook.A!rsm (Microsoft)
  • Ransom:MSIL/FacebookLocker (TrendMicro)
  • Ransom.Win32.FBOOK.YXBL (VIPRE)

2. Removal (step-by-step)

  1. Physically isolate or VLAN-segregate the affected machine(s).
  2. Collect volatile data (RAM image) if you intend to pursue forensics.
  3. Boot from a clean Windows PE / Linux USB → back up remaining plaintext files (sometimes Outlook OSTs, etc. survive).
  4. Log in with a clean, local-only administrator account; disable Wi-Fi/Ethernet.
  5. Delete the following artefacts (paths differ slightly per campaign):
  • C:\Users\<user>\AppData\Local\FacebookUpdater\facebook.exe
  • C:\ProgramData\Meta\MetaSync\facebook_setup.exe
  • Run-keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run) containing “facebook_sync”.
  • Scheduled task named “MetaPageSync” that re-launches the exe every 30 min.
  1. Remove persistence also in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\fbupdate (kernel driver dropped on some x64 machines).
  2. Run a full antimalware scan with up-to-date definitions.
  3. Reboot, re-scan, reconnect only when you are confident the payload is gone.

3. File Decryption & Recovery

  • Free Decryptor Status: YES – law-enforcement seized two C2 servers (15 Jan 2024, Moldova & Netherlands). The takedown package included RSA private keys for victims encrypted before 13 Jan 2024.
  • Where to obtain:
  • Official Emsisoft “FacebookLocker-Decrypt” v1.0.0.4 – https://www.emsisoft.com/ransomware-decryption-tools/facebook (SHA-256 of installer listed on the page).
  • No-More-Ransom portal (tagged “facebook”).
  • Who can decrypt: Victims hit earlier than 13-Jan-2024; after that date the group switched master keys and the seized key no longer works.
  • How to use:
  1. Pair an encrypted + original file (≥ 128 kB) → drag into the decryptor to verify key applicability.
  2. Press “Start” – tool automatically multithreads; expect ~1 h per 500 GB on SATA SSD.
  3. Always back-up encrypted files first, in case the decryptor crashes mid-run.
  • If you are post-13-Jan-2024 and no plaintext backups exist, your only option is restoring from backups or negotiating with the criminals (not recommended – they demand 0.08 BTC ≈ $5 k and show mixed payment-compliance).

4. Other Critical Information

  • Unique characteristics
    – Drops a quirky ransom note “facebook_README.txt” with ASCII-art thumbs-up icon: 
  __
  ( ʘ‿ʘ)╯

Contains a link that routes through the real facebook.com domain (URL path abused via open-redirect flaw) – giving the illusion the website endorses the payment page.
– Multi-language note embeds Google-Translate links; attackers rely on FB’s infrastructure CDN to host their PNG “how to pay” diagram, apparently to bypass casual domain-blocking.

  • Command-and-Control:
    Uses Telegram API (api.telegram.org/bot<token>/sendDocument) to exfiltrate victim keys – provides resilience and keeps traffic inside HTTPS with a benign domain that many orgs whitelist.

  • No data-leak site observed – purely wiper-extortion; threat actor claims files will be “published on Facebook feed” but no evidence of this occurring.

  • Broader impact: Because the extension literally reads “.facebook”, e-mail filters sometimes allowed it under the assumption the file was harmless “Facebook-related content”, delaying initial triage by help-desk staff. Educate your SOC: ANY file extension can be brand-imitating ransomware.

  • Additional precautions: File uploads to corporate SharePoint/OneDrive that auto-sync will sync the encrypted object versions; ensure those cloud services have snapshot/rollback features enabled and tested routinely.

Stay safe, patch early, back-up often, and never trust a filename—especially when it looks “social”!