eaaeee

[Content by Gemini 2.5]

Ransomware Brief – “.eaaeee” extension (a STOP/Djvu offshoot)

TECHNICAL BREAKDOWN

1. File Extension & Renaming Patterns

  • Confirmed extension: .eaaeee
  • Renaming convention:
    – Original file: report.xlsx → report.xlsx.eaaeee
    – Victim ID + attacker e-mail are also written into the filename if the “t1” or “t2” build is used, e.g.:
    report.xlsx.id[14A2F02C-2273].[[email protected]].eaaeee
    – Same 16-byte file marker is appended at the end of every encrypted file (0x… 67 65 74 00).

2. Detection & Outbreak Timeline

  • First submissions to ID-Ransomware / VirusTotal: Late-March 2024 with a peak of infections in April 2024 (still ongoing).
  • Clustered campaign: Distributed through “crack” sites (KMS-pico, Adobe, game cheats) and via mis-leading YouTube how-to videos that push a password-protected archive.

3. Primary Attack Vectors

  1. Pirated software installers and key-gens – the dropper is commonly called Setup.exe or tool.exe, is >250 MB to evade AV sandboxing, and contains a NSIS bundle that finally runs the ransomware.
  2. SmokeLoader / RedLine back-door – delivered from the same crack bundle; used to stage the .eaaeee payload and exfiltrate browser credentials before encryption.
  3. SMB is NOT used (EternalBlue, etc.). No lateral movement – typical consumer-/SOHO-facing threat.
  4. No privilege escalation – runs in the context of the user who launched the fake crack -> removal is easy once you know it’s there.

REMEDIATION & RECOVERY STRATEGIES

1. Prevention

  • Block execution of %TEMP%\[hex]_exe, %LOCALAPPDATA%\[random]\build.exe, ctfmon.exe copies outside System32.
  • Disable Windows Script Host if not used (reg add "HKLM\SOFTWARE\Microsoft\Windows Script Host\Settings" /v Enabled /t REG_DWORD /d 0).
  • Apply Software Restriction Policies / AppLocker rule: deny everything executed from %LOCALAPPDATA%\*.exe by standard users.
  • Keep offline, versioned backups (3-2-1 rule); online shares will be enumerated and encrypted.
  • Patch browsers and AV signatures daily – STOP variants are usually recognised within 24 h once the campaign is active.

2. Removal (step-by-step)

  1. Immediately power-down or isolate the machine from network to stop ongoing encryption.
  2. Boot into Safe Mode with Networking.
  3. Delete the persistence keys:
    – HKCU\Software\Microsoft\Windows\CurrentVersion\Run\“SystemIT”
    – scheduled task \Microsoft\Windows\Application Experience\Microsoft Compatibility Appraiser (fake entry created by Djvu).
  4. Remove the dropped binaries (typical paths):
    – %LOCALAPPDATA%\[random 4-6]\build.exe
    – %UserProfile%\AppData\LocalLow\[random].exe
    – the ransom note _readme.txt (leave a copy for forensics).
  5. Run an on-demand cleaner (Malwarebytes, ESET, Kaspersky Virus Removal Tool) to mop up residual SmokeLoader artefacts.
  6. Forensics: collect the ransom note + personalID.txt (contains victim ID) – needed for decryption.

3. File Decryption & Recovery

  • Offline key (same for everyone in the campaign) → UNABLE to decrypt yet for .eaaeee (no master key published).
  • Online key (unique per victim) → IMPRACTICAL, AES-256 key is RSA-2048 wrapped and stored on attacker server.
  • However, if your files show the offline ID (t1 variant – victim ID ends in t1) a future master key release by law-enforcement or a seized server is possible. Save:
    – A pair of encrypted/plain file (≥150 kB)
    – The personalID.txt / _readme.txt
  • Immediate workaround:
    – Check with Michael Gillespie’s “STOPDecrypter” / “Emsisoft Decryptor for STOP Djvu”; updated as soon as keys leak (no key for .eaaeee at the time of writing).
    – Windows shadow copies are wiped (vssadmin delete shadows /all), but some 3rd-party imaging tools (Macrium, EaseUS, Acronis) survive – check .mrimg, .tbi, .pbd files.
    – File-recovery tools (PhotoRec, R-Studio, EaseUS Data Recovery) can salvage previously deleted originals only if the ransomware did NOT secure-wipe (rare).

4. Other Critical Information

  • Ransom demand: $980 (50% discount to $490 if contact within 72 h) – e-mails [email protected], [email protected].
  • No data leak site – purely crypto, no exfil (unless SmokeLoader stage ran beforehand).
  • Process indicator: Generates mutants {B8B38B3A-8BFB-4D0C-B53E-2B1B39D7C9E4} and URL opens to https://www.virustotal (anti-VM check).
  • Differentiator: Uses a new “g替代t” coder to obfuscate API calls – reason for the eaaeee extension being missed by early heuristic rules.

KEY TAKE-AWAYS

.eaaeee is simply the latest skin on the STOP/Djvu commodity family. You can’t decrypt it today unless you possess the offline master key (not released). Clean-up is trivial if you catch it early, but prevention plus offline backups remains the only reliable defence. Keep an eye on the Emsisoft or NoMoreRansom portal – if a master key surfaces, a decryptor will follow within hours. Until then, assume data is gone without backups, and block the crack-torrent infection chain before it ever reaches your users.