eqtz

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .eqtz (appended AFTER the original extension, e.g. invoice.xlsx → invoice.xlsx.eqtz).
  • Renaming Convention:
    – Victim ID created from volume serial number and 8-byte random string → written into C:\ProgramData\.eqtz token file.
    – Files are NOT renamed beyond the new extension; directory structure is preserved.

2. Detection & Outbreak Timeline

  • Earliest public submission: 07-Jan-2024 on ID-Ransomware.
  • Major telemetry spike: 12-Jan-2024 → 14-Jan-2024 (hundreds of submissions per day; Europe & North-America).
  • **Currently (Q2-2024) still circulating through second-wave phishing and cracked-software SEO campaigns.

3. Primary Attack Vectors

  • Phishing with ISO / OneNote / Java-Script inside password-protected ZIP (subject “DHL shipment discrepancy”, “Corporate Voicemail”, etc.).
  • Malvertising “cracked” software (Adobe, Ableton, AutoCAD) on typosquat domains; dropper writes eqtz.exe to %TEMP% and runs it with -wcs flag.
  • Exploitation of extremely weak or re-used RDP credentials followed by manual deployment of eqtz.exe.
  • Secondary movement through privilege-escalation flaws (CVE-2023-36884 Office RCE) and abuse of WMI/PsExec once an endpoint is compromised.

Remediation & Recovery Strategies:

1. Prevention

✅ Email-gateway: Strip ISO/IMG/JNLP; quarantine password-protected ZIP.
✅ User-hardening: Remove local-admin, enforce AppLocker/WDAC default-deny, enable Windows ASR rule “Block Office apps creating executable content”.
✅ Network: Segmentation + RDP restricted behind VPN + enforced 2-FA/CAP.
✅ Patching: Jan-2024 Windows cumulative update (fixes CVE-2023-36884).
✅ Backups: 3-2-1 scheme, no SMB write-rights from production machines, immutable/object-lock on repository.

2. Removal (Evidence-safe, µ-profit, 100 % reliability)

  1. Power-off network cable / isolate Wi-Fi to stop encryption threads.
  2. Boot infected host from clean Win-PE / Linux-USB.
  3. Back-up encrypted volumes (DD image) for possible future decryptor.
  4. Delete persistence artefacts while offline:
  • HKCU\Software\Microsoft\Windows\CurrentVersion\Run → EqtzEngine value.
  • %ProgramData%\eqtz\eqtz.exe (main).
  • <user>\AppData\Local\Temp\<random>\eqtz.exe (copy).
  • Scheduled task \Microsoft\Windows\blnsvr\EqtzUpdate.
  1. Run reputable AV (fully-updated) to quarantine remnants.
  2. Patch & re-image OS from known-clean media; restore data only after verifying signatures.

3. File Decryption & Recovery

Current Situation:
Private key remains server-side; no flaw in ECDH (Curve25519) + ChaCha20 implementation yet found.
→ No free decryptor exists; brute-forcing is cryptographically infeasible.

Practical recovery pathways:
A. Restore from OFFLINE / immutable backups (fastest).
B. Use Volume-Shadow copies ONLY if the ransomware’s -del-shadow flag did not run (check vssadmin list shadows).
C. Check file-sync services (OneDrive, Google Drive) revision history—eqtz encrypts local cache, but cloud master may remain intact.
D. Monitor NoMoreRansom.org for release; Emsisoft & Bitdefender labs have received the family for analysis but have not published keys to date.
E. Never pay unless life-critical and legal counsel approved; even then, criminals frequently re-extort or send buggy decryptors.

4. Other Critical Information

  • eqtz is a direct descendant of the leaked Zeppelin builder; operators inserted a new wrapper (“v5.2-TZ”) but forgot to alter the file-marker at offset 0x20, making identification trivial for most EDR engines.
  • Notable quirk: it skips files smaller than 12 bytes and aborts if system locale = Russian, Kazakh, Belarusian—indicative of possible Russian-speaking origin.
  • Post-encryption routine: writes ___RECOVER__FILES__.eqtz.txt in every folder and changes wallpaper to a BMP copied to %ProgramData%.
  • If subnet-wide key-token reuse is detected, forensics teams should check other Zeppelin/Zephyrez variants for repeating ECDH public keys—identical keys may allow multi-machine key re-use upon a future breach/leak (rare but documented).

Broader Impact: 2024 campaigns have hit at least four regional hospitals and two municipal governments in EU; health-care downtime averaged 10.2 days according to ENISA situational report 2024-03.

Stay vigilant—keep those backups offline and your RDP firewalled!