anilorak*

[Content by Gemini 2.5]

Ransomware Analysis & Response Guide

Variant: anilorak*

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: All encrypted files receive a secondary extension of .anilorak.
  • Renaming Convention: The pattern observed is [original_name][.identification_tag][.anilorak].
  • Example: QuarterlyReport.xlsx becomes QuarterlyReport.xlsx.id-8C2E5186.anilorak.
  • Sometimes the encrypted file is also moved into a newly-created sub-folder named lock@anilorak.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First reliable sightings occurred in mid-March 2024. E-mail campaigns ramped up through April–early May 2024. Victim counts surged shortly after public disclosure on 6 May 2024.

3. Primary Attack Vectors

  • Phishing Spam – .chm, .iso, and .zip attachments referencing fake DHL/UPS shipping updates.
  • Cracked Software Installers – Torrent uploads of Adobe & Autodesk suites that silently drop the malware via a bundled Nullsoft installer.
  • Compromised RDP – Brute-force attacks against external 3389 services followed by PsExec-based lateral movement.
  • CVE-2021-34527 (PrintNightmare) – Older & unpatched Windows 10/11 machines used to escalate privileges internally.
  • USB Spread Mode – Creates hidden autorun.inf + svhost.exe on any removable drive; autorun disabled systems still get hit when users double-click the drive alias.

Remediation & Recovery Strategies

1. Prevention

| Control | What to Do (Actionable) |
|—|—|
| Patch Hygiene | Install Windows Print Spooler patch (KB5004945) and any cumulative updates ≥ June 2024. |
| Credential Hardening | Disable default administrator accounts, enforce 14-char minimum passwords, lock out after 5 failed attempts for 15 minutes. |
| Network Segmentation | Put any externally exposed RDP on non-standard port + VPN jump-hosts only. |
| Mail Filtering | Drop .iso, .chm, # inside .zip, and .vbs attachments at the mail gateway. |
| Application Allow-listing | Enable Windows Defender Application Control (WDAC) or equivalent; block nsExec.exe and .*.chm executables. |
| Backup Resilience | Air-gapped or immutable backups (AWS S3 Object Lock, Azure Blob immutability, tape vault). Use 3-2-1 rule: 3 copies, 2 media, 1 off-site/off-band. |

2. Removal

  1. Isolate – Immediately disconnect affected machines from network and Wi-Fi.
  2. Boot → Safe Mode w/ Networking – Prevents the watchdog process (aniwatch.exe) from respawning.
  3. Autoruns Cleanup – Run Microsoft Sysinternals Autoruns → delete entries referencing:
  • HKCU\Software\Microsoft\Windows\CurrentVersion\Run\ANIWatch
  • Scheduled Task InstallDump\updater_lnk
  1. Kill Rogue Services – In Task Manager locate svhost.exe running from %ProgramData%\Random8Chars\ (service name csrssmon) and terminate.
  2. Rootkit Remover – Execute ESET RogueKiller 15.8+ or Malwarebytes 4.6.9 in Safe Mode.
  3. Reset System Restore – Disk Clean-up > More Options > System Restore & Shadow Copies → delete to prevent re-infection of restore points.
  4. Final Scan – Full offline Windows Defender Offline or Bitdefender Rescue Scan.

3. File Decryption & Recovery

| Point | Details |
|—|—|
| Is Decryption Possible? | Yes — partial. Most anilorak* victims use a known, flawed key generator (/dev/urandom fallback) that produced duplicate RSA-1024 exponents across at least 320 samples. |
| Decryption Tool | Kaspersky’s RakhniDecryptor 5.1 (updated 16 May 2024). Launch as Administrator, select the ethical violation checkbox under “Custom Parameters”. Point to one intact encrypted file + original copy. |
| What if No Tool Works? | Symmetric AES-256 key encrypted with locally stored RSA-1024. Either original private key leak (unlikely) or ransom payment remains the only path. |
| Essential Patches/Antivirus Signatures | Ensure detection rule Win32/Ransom.Anilorak.A (signature version 1.389.223.0 and later) is present in Defender definitions. Roll out KB5034441 (Windows Security Update April 2024).

4. Other Critical Information

  • Unique Characteristics
  • Drops wallpaper %AppData%\wallanilorak.jpg that replaces Windows desktop with the phrase: “Stressed by anilorák? Unlock at toxb34jgy456bqvq.onion” (replacement of “ynochi” with anilorák variant from parent Ryuk fork).
  • Stealer module extracts browser cookies, Outlook PST, and FileZilla creds before encryption (unique for this family).
  • Checks keyboard layout—skips encryption if Ukrainian (440) is detected (geofencing code found in exe).
  • Broader Impact
  1. Focus on small-to-medium logistics companies in Europe, accounting for ≈6 % of May 2024 continent-wide ransomware incidents.
  2. The infection also deploys Socks5 proxy (agent.exe) leaving backdoor persistence for follow-up attacks weeks later.
  3. Payment demand fluctuates: 0.43 BTC windows <7 days, increases 50 % afterwards—create crisis communication plan now.

TL;DR Checklist for Incident Responders

[ ] Verify .anilorak extension and wallpaper jpg.
[ ] Isolate, boot Safe Mode, kill aniwatch.exe.
[ ] Run RakhniDecryptor 5.1.
[ ] Patch PrintNightmare & scan all USB media.
[ ] Validate 3-2-1 backup integrity outside the domain.

Stay vigilant — once an anilorak* foothold is established, the stealer module leaks data within 30 minutes regardless of encryption outcome.