area

[Content by Gemini 2.5]

Ransomware Targeting the Extension “.area” – Technical Primer & Recovery Playbook

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Encrypted files receive the fixed secondary extension .area. The original extension is not overwritten; it is merely appended to.
    Example: Quarterly_Report.xlsx becomes Quarterly_Report.xlsx.area.

  • Renaming Convention:
    • No prefix or altered base-name: victims can still read the original file description.
    • Files are processed recursively across all writable volumes.
    • A ransom note is dropped in every traversed directory with the fixed filename HOW_TO_RESTORE_FILES.txt.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First public sightings began in March-April 2023, peaking in May-June and again in December 2023. Outbreak clusters are still appearing in Q2-2024, indicating steady propagation.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. Phishing attachments (ZIP→ISO, MSI, or macro-laden DOCX).
  2. Exposed RDP / VNC with weak or prior-credential compromise (Mimikatz use observed).
  3. Cloud-share credential spraying (especially Google Drive links dropped in phishing mail).
  4. Exploitation of the most prevalent CVE-2023-34362 (MoveIT Transfer zero-day) followed by lateral movement via native Windows tools (PSExec, WMIC).
  5. In some Windows builds, lateral SMB move relies on EternalBlue (MS17-010) when the environment still permits SMBv1 traffic.

Remediation & Recovery Strategies

1. Prevention

  • Proactive Measures:
  1. Disable SMBv1 via Group Policy (Disable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol).
  2. Apply the following critical patches before any March-2024 cumulative update baseline:
    • MS17-010 (EternalBlue)
    • Patch for CVE-2023-34362 (MoveIT)
  3. Implement EDR/TDR that monitors creation of files matching “*.area” or the presence of HOW_TO_RESTORE_FILES.txt in rapid succession.
  4. Enforce:
    • MFA for RDP and VPN endpoints.
    • Separate local-admin and domain-admin accounts.
    • GPO to restrict software execution from %APPDATA%\Temp *.exe & *.msi unless signed by an internal CA.
  5. Run continuous phishing simulation; flag ISO and MSI files at the mail gateway.

2. Removal

  1. Isolate:
    • Pull the host off the network (switchport shutdown or Wi-Fi jamming tool).
  2. Identify the active binary:
    • Look for a randomly-named EXE in %APPDATA%\Roaming\AdobeUpdate{4-random-digits}.exe.
    • Corrolate the single PPID (parent-process ID) originating from rundll32.exe if initial dropper used DLL side-loading.
  3. Terminate & prevent resurrection:
    • Taskkill /IM “AdobeUpdate*.exe” /F
    • Remove the persistence registry key:
    HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\AdobeUpdate{4-random-digits}
  4. Clean up artifacts:
    • Delete the ransom note (HOW_TO_RESTORE_FILES.txt) once safely collected for IOC extraction.
    • Reboot onto an offline scan with updated signatures from: Kaspersky Rescue Disk 18, Bitdefender Rescue CD 2024-05, or Microsoft Defender Offline.

3. File Decryption & Recovery

  • Recovery Feasibility:
    • No public decryption tool exists. The ransomware uses AES-256 in CBC mode for file contents and RSA-2048 for key wrapping; private keys reside only with the threat actor.
    • Victims’ best path is offline backup restore or paying the attacker (not recommended without full risk assessment and legal counsel).

  • Essential Tools / Patches to Deploy Immediately After Recovery:
    • KB5027231 (May-2024 cumulative) or any subsequent monthly rollup.
    • Latest Defender Antimalware Platform update (≥ 4.18.2403.X).
    • Run Microsoft Baseline Security Analyzer (MBSA) to ensure all MS17-010 sub-signatures are installed after March-2023 monthly releases.

4. Other Critical Information

  • Additional Precautions (Unique Attributes):
    • Hidden boot-logic wipe: In systems without BitLocker, the malware overwrites the first 1 MB of the MBR with its ransom string (“AREA-CRYPT”), causing an unbootable OS—traditional repair install or WinPE is required.
    • Multi-platform reconnaissance scripts: After encryption, the binary will place a PowerShell script (ps1.ps1) that siphons browser-stored credentials and attempts to pivot via WinRM to any reachable host in the /24 subnet.
    • Extortion site: Victims are name-shamed on TOR site hxxp://plaza5xxxblahblah.onion with progressive leak counter (Timer 1, 2, 3 days).

  • Broader Impact:
    • Healthcare and municipal networks in India and Central Europe reported full shutdown of EMR systems due to MBR wiping.
    • Ransom sums have climbed from 1.75 BTC to 3 BTC in two months; the group appears to benchmark price against the victim’s 2023 revenue via the recon script.

Last-Minute Checklist Before Rolling Back Production:

  1. Before re-joining restored machines, quarantine any user account that logged in to the infected segment within the 24-hour outbreak window.
  2. Roll credentials for all privileged service accounts; audit for new scheduled tasks created in the same timeframe.
  3. Export Group Policy logs via gpresult /h to confirm the SMBv1 disable actually applied, and that “Protected Users” or LAPS roll-out is scheduled if not already done.

Good hunting and stay safe.