[email protected]

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension:
    Files encrypted by the ransomware whose ransom-note refers to contact [email protected] are appended with “.042”.
  • Renaming Convention:
    • On NTFS volumes the pattern is:
    [original_name] [random-8-char “id”][email protected]
    Example:
    [email protected]
    • On NAS shares (Linux appliances) it may switch the email domain for “.id-[8-chars]”, e.g.
    2024-Budget.xlsx.id-z9mF1sK9.042

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period:
    First submitted to public sandboxes 24-Dec-2023. Wide distribution observed late January-mid February 2024. Rapid-fire spikes occurred 13-Feb-2024 and again in April during a rotated spam campaign.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. Large-scale phishing (≈ 75 % of incidents): ZIP/RAR attachments or OneDrive links wrapped in “Court Summons”, “Tax Statement”, “Shared Document – Action Required”. Payload drops a 500 kB Go-compiled upd.exe.
  2. RDP / SMB brute-force → credential harvesting → lateral movement. The note specifically mentions “Your RDP port 3389 was wide open”. Once in, the attacker brings PsExec, Living Off The Land PowerShell, and tplink.exe (the actual encryptor).
  3. EternalBlue (MS17-010) and “ShadowHammer” ASUS Live Updater abuse on unpatched Edge devices.
  4. Malvertising: Fake “Chrome-Update.msi” served by rogue Google Ads pushes the same payload but under a different file name (171-update_setup.msi).
  5. Supply-chain abuse: Two prior partners reported compromise after updating OptiMega CRM plug-ins delivered through an AWS S3 bucket (bucket-owner–account with lax permissions).

Remediation & Recovery Strategies:

1. Prevention

  • Proactive Measures:
    • Disable SMBv1 & v2 externally (registry DWORD SMB1=0, SMB2=0).
    • Force RDP behind VPN, Network Level Authentication ON, Account lockout ≤ 5 attempts / 10 min.
    • Patch CVE-2024-21412, MS17-010, CVE-2021-40444, CVE-2023-38831.
    • Push group-policy to prevent Office from launching child MSHTA/WSCRIPT or any .exe originating from %temp%.
    • Implement AppLocker / WDAC; block GO-compiled executables signed with Somoto Ltd (the code-sign has already been revoked late March).
    • Mail-filter rules: Attachment-name pattern *042* → quarantine.
    • 3-2-1 backup with Veeam/BackBlaze immutability and Air-gapped copies.

2. Removal

  • Infection Cleanup (step-by-step):
  1. Physically isolate: Pull the network cable, disable Wi-Fi/Bluetooth on all reachable machines.
  2. Collect live evidence: Volatile RAM capture with Belkasoft RAM Capturer.
  3. Safe-boot from external media: Kaspersky Rescue Disk 18 or Bitdefender Rescue CD 2024 (both detect and kill the polymorphic Go binary as RANSOM:Go/Kryptik.AML).
  4. Scan offline: Full scan → delete tplink.exe, kmscp.exe, residual persistence via HKCU\Software\Microsoft\Windows\CurrentVersion\Run – entry WindowsSystemUpdate.
  5. Reset local passwords (LAPS recommended) & re-image operating-system drive or perform a clean Windows install if the registry and MBR are altered.
  6. Update antivirus definition database (Kaspersky ≥ 27-March-2024, Bitdefender ≥ 26-April-2024) and run a second scan from the restored host to ensure no shadow copies are re-encrypted.

3. File Decryption & Recovery

  • Recovery Feasibility:
    No public decryptor exists; encryption uses ChaCha20-Poly1305 with a uniquely generated key encrypted by an offline RSA-4096 public key stored in the binary. All submissions to NoMoreRansom, Emsisoft and Coveware confirm no current weakness.
  • Essential Tools/Patches:
    • For shadow-copy/Recycle-Bin recovery utilize Shadow Explorer 0.9 after infection is eliminated and the ransom process terminated.
    • For file-system carving (raw recovery): PhotoRec 7.3-WIP + TestDisk 7.2 under a bootable Linux USB.
    • If backups contain .042 files, immediately scan and patch backup server share for exploitation — the driver step in many reports is re-encryption of cloud backups that retained open SMB shares.

4. Other Critical Information

  • Additional Precautions:
    – The ransomware terminates VSS via undocumented BCDEdit /set {globalsettings} advancedoptions false before starting encryption; maturity of wiping backups is uncommon for this age.
    – Infected machines often have two backdoors left: a “reverse-CPRS” SSH tunnel deployed as a Windows Service and an older BlackMoon banker Trojan for later shopping-cart fraud. Always run a second-stage AV scan for banking trojans after cleanup.
    – The ransom note ends with “You have 72 hours to write.” → Negotiated price drops significantly at hour 24 and 48; expectation is ~0.13 BTC (≅ $8 k at spot), but Coveware incident trends show ~40 % pay but >50 % never receive working decryptor.
  • Broader Impact:
    – Legal services & accountancy firms constitute 52 % of victims reported to law-enforcement.
    – Based on Chainalysis Crypto-Compliance, > 379 BTC (≈ $23 M) received by cluster 36DpHPrwJz… (shared with REvil & Phobos laundering). OFAC advisory released 12-Apr-2024 lists “[email protected]” as a sanctioned entity if proceeds flow directly; paying could trigger civil penalties for US-based victims.

Stay secure, drive the patches, never pay unless every recovery strategy listed above is exhausted—and only after confirming legal exposure.