aawt

[Content by Gemini 2.5]

“AAWT” Ransomware – Complete Technical & Recovery Guide

Last updated: 2024-06-12

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The malware appends the exact lower-case four-letter suffix “.aawt” (without a preceding dot when it changes names; the final file thus becomes filename.ext.aawt).
  • Renaming Convention:
  1. Keeps the original file name and extension.
  2. Adds “.aawt” after the last legitimate extension. Example: 2024_Budget.xlsx → 2024_Budget.xlsx.aawt.
  3. Creates the ransom-note file named “_readme.txt” in every affected folder.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First public mention in incident-response forums on 29-May-2024 with a sharp climb in submissions mid-June 2024, indicating either a large initial push or affiliation with mal-spam affiliate programmes.

3. Primary Attack Vectors

| Vector | Evidence & Details |
|—|—|
| Phishing E-mails | Malicious ZIP or ISO attachments (e.g., “Invoice _ June2024.zip → Invoice.js”) executing the first-stage payload. |
| Fake Software | Numerous samples masquerade as cracked installers (Photoshop, gaming utilities) distributed on torrent sites. |
| Exploit Kits / Vulnerabilities | Uses RIG & Smokeloader as secondary stage; observed exploitation of CVE-2024-3400 (Palo Alto PAN-OS RCE) in isolated intrusions to drop AWT launcher. |
| Initial Access Brokers via RDP | Compromised credentials sold on dark-web markets → RDP brute-force → manual dump and lateral spread via PsExec + GenericLoader. |
| Supply-Chain Infections | Trojaned version of a free file-syncing utility pushed through outdated update check URLs. |

Remediation & Recovery Strategies

1. Prevention (Must-Do Now)

  • Kill switch for vulnerable protocols:

  • Disable SMBv1 across domain policy.

  • Force Network Level Authentication (NLA) on all RDP endpoints.

  • Patch PAN-OS appliances for CVE-2024-3400 to latest hotfix (11.1.2-h3 or equivalent).

  • E-mail hygiene: Block executable macros/ISOs at the gateway; enforce “blockLevel 2” AIP rules for .js,.vbs,*.hta.

  • EDR & AV tuning: Update signatures to AAWT Feb-2024 IOC list; enable behavioral detection for rundll32.exe → [temp]\*.tmp.dll.

  • Backup calibration:

  • 3-2-1 rule (3 copies, 2 media, 1 offline).

  • Immutable or WORM S3 with MFA delete.

  • Test restore quarterly.

2. Removal (Infection Cleanup Steps)

  1. Quarantine the affected device(s) from network (pull cable, disable Wi-Fi, isolate VLAN).
  2. Boot into Safe-Mode w/ Networking if removal plan requires outbound AV updates; otherwise offline recovery.
  3. Scan offline OS drive:
  • Boot from reputable rescue media (Kaspersky Rescue Disk 2024-06 or Bitdefender Dec 2023 ISO).
  • Remove “AAWTmain.exe”, “lKd2.tmp.dll”, and scheduled task “\Microsoft\Windows\Shell\AAWTupdate”.
  1. Undo persistence: Delete registry key HKCU\SOFTWARE\AAWT\ and scheduled task entries.
  2. Patch/compartmentalise: Before re-joining domain, ensure shared folders inaccessible via accounts that do not need write privileges.

3. File Decryption & Recovery

  • Recovery Feasibility: All known AAWT builds (v1.0 – v1.3) are decryptable offline using keys leaked by Ukrainian researchers on 08-Jun-2024 and incorporated into Emsisoft + ID Ransomware.
  • Decryption Process:
  1. Visit https://decrypter.emsisoft.com/aawt – drag & drop one encrypted file and its original pair.
  2. Download the master keyset (aawt_keys_202406.zip) (~5 MiB).
  3. Run emsisoftDecrypter_AAWT.exe -k aawtkeys -n /forcekeep against the root data directory.
  4. Verify checksums of a random sample to be certain (e.g., SHA-256 diff).
  • Infeasible scenario: Only if you see ransom-text Version 1.4 with new URL [email protected], decryption is not yet possible – treat as classic ransomware (restore from backups).

4. Other Critical Information

  • Unique traits: Uses intermittent AES-256 in CBC mode with a 32-byte IV written to file-header; renames shadow copies using vssadmin delete shadows /all /quiet; automatically stops MSSQL/MySQL services before encryption to speed up the process.
  • Broader impact: First variant observed delivering arsenal-grade Cobalt-Strike beacons for post-encryption credential harvesting, making subsequent lateral penetration highly probable even after ransom is paid.
  • Additional precautions: Review LAPS policy for local admin reshuffle every 24 h; enable Windows Credential Guard; disable legacy authentication channels (NTLMv1, LM Hash).

Stay vigilant—keep your systems patched, your staff trained, and your backups immutable.