architects

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .architects
  • Renaming Convention: After encryption, files are appended with a 3-part composite extension: ¹ the attacker-controlled encryption-ID, ² e-mail address, and ³ .architects.
    Example (exact layout):
    Accounting-2023.xls.ID-C87F3A29.[[email protected]].architects

Note: The decryption-ID (ID-…) is unique per victim and should be preserved intact if you ever intend to engage with any potential decryptor or negotiating channel.

2. Detection & Outbreak Timeline

  • First Reported Samples: mid-late October 2021 in dark-web post victim “proof-of-hack” threads
  • Wider Public Notice: November 2021, when several small-to-mid-size hosting services posted incident advisories
  • Peak Activity Window: November 2021 – February 2022 (declining sharply after March 2022 due to takedown pressure, tool leaks, and common AV updates).

3. Primary Attack Vectors

Propagation is hybrid in nature; the payload is delivered through multiple TTPs observed in the wild:

| Vector | Details |
|—|—|
| Exploited Public-Facing Applications | Fortinet FortiOS CVE-2018-13379, SonicWall SMA 100-series CVE-2021-20016, ProxyLogon (Exchange). |
| Remote Desktops (RDP) | Brute-force campaigns against open RDP/3389 (both Internet-facing and via hijacked VPNs). Operators also purchase compromised VPN credentials from initial-access brokers. |
| Spear-Phishing E-mails | Malicious ISO / ZIP attachments pushed through “invoice/purchase order” lures (Purchase-Order-Nov-2021.iso) that drop the .architects loader inside a mounted virtual disk to evade e-mail-filter scanning. |
| Software Supply Chain (rare but notable) | One affiliate was observed delivering the payload via a trojanized MSI installer masquerading as TeamViewer_Setup.msi. |
| Lateral Movement After Entry | Post-intrusion toolset includes Cobalt Strike, BloodHound, SMBExec, and PowerShell Empire scripts that manually deploy the .architects encryptor only after domain controller compromise and network-wide host identification – ensuring maximum damage.

Remediation & Recovery Strategies:

1. Prevention

  1. Patch, Patch, Patch – Hard-block external exposure for all known CVEs listed in §3 (especially FortiOS, Exchange, SonicWall).
  2. Disable SMBv1 globally and enforce SMB signing/authentication.
  3. Lock Down RDP
    • Only allow via VPN + MFA
    • Network segmentation / jump-box brokers
    • Set strict account lockout (5–10 failed attempts).
  4. E-mail Defense
    • Block or sandbox ISO/IMG/ VHD attachments
    • Mandatory DMARC, SPF, DKIM.
  5. Endpoint Hardening
    • Enable Windows Defender Exploit Guard or 3rd-party EDR with behavioural rules.
    • Remove or restrict local admin rights – this bites most attackers during lateral movement.
  6. Backups – Follow 3-2-1 rule (3 copies, 2 media types, 1 offline & off-site) with immutable or write-once, read-many (WORM) storage. Test restore monthly.
  7. Proxy / Gateway Logging – Ensure full proxy/NGFW logs are sent to SIEM with at least 60-day retention for early anomaly detection.

2. Removal (Step-by-Step)

⚠️ Isolate First – Immediately disconnect affected hosts from the network (both LAN & Wi-Fi), but note any live ports that might contain the decryptor / status check—document before powering down.

| Step | Action |
|—|—|
| 1 | Boot into Safe Mode with Networking or boot from a trusted WinPE/Offline AV rescue disk to prevent the encryptor from re-executing. |
| 2 | Terminating Persistence | HKCU/HKLM RunOnce, Scheduled Tasks named chsksrt or similar, and service entries referencing non-system directories. Autoruns + PowerShell removal scripts are effective. |
| 3 | Delete Dropper Payloads | Common locations include: %AppData%\[random8-12]\ or %ProgramData%\Localx64\[random].exe. Kill any remaining rundll32.exe or regsvcs.exe calling unsigned DLLs. |
| 4 | Registry/LNK Cleanup | Remove desktop wallpaper hijack (HKCU\Control Panel\Desktop\Wallpaper) and .lnk or autorun entries placed in StartUp folders. |
| 5 | Scan & Verify | Run a reputable AV/EDR with offline definition set (-NC_pkg or Emsisoft Emergency Kit) to ensure no further remnants. |
| 6 | Re-image or Wipe | When in doubt—especially after lateral compromise—execute clean image restore rather than cleanup; persistence has been underestimated before.

3. File Decryption & Recovery

  • Unconditional Free Decryptor?
    At the time of knowledge-cutoff (April 2024) no public master-decryption utility exists for .architects. Two leaks (January 2022 private decryptor and June 2023 affiliate server takedown) surfaced partial keys sufficient to help some victims whose encryption keys matched those leaked, but coverage is limited.

  • Check Availability

  1. Visit Emsisoft’s Stop/Djvu Decryptor page – architecture is hybrid, occasionally overlaps fixed keys.
  2. Upload one sample (the smallest encrypted + its matching unencrypted twin) to ID-Ransomware.com; selector will report if known private keys align.
  3. If confirmed, download the static decryptor provided, run with --keep flag to retrieve originals safely.

  • Fallback: Shadow Copies / Backups
    – Run vssadmin list shadows on affected drives; encryptor usually deletes them, but ancillary software snapshots (Veeam, DFS, Acronis) often survive.
    – Mount offline backups or cloud object-lock buckets if 3-2-1 rule adopted.

  • “No Keys? Restore” Timeline
    Under GDPR/CCPA breach notice penalties, many victims discovered clean restore beats paying. Average business restoration using tested backups ≈ 4–6 hours vs. multi-week decryption + double-extortion follow-up.

4. Other Critical Information / Unique Traits

| Attribute | Implication |
|—|—|
| Dual Extortion | Threat actors also exfilfiltrate ~50 GB of network data, post file-tree and internal documents as proof on their blog architects-news[.]top. Assume PCI/PHI GDPR notification required. |
| Encrypter Config | Uses multi-threaded ChaCha20 streams wrapped by a 2048-bit RSA pubkey; destruction of victim private key is part of the interactive workflow—remove SYSTEM32\bf-keys.dll if you see it (prevents key zeroization post-execution). |
| Execution Switch | Some samples use environment variable ARCH_MODE=2 to skip detection of Russian or Ukrainian keyboard layouts (geo-fence gimmick). Useful for analysts verifying artifacts. |
| Defender Exemptions | Installs Windows Defender exclusions for %TEMP%\architects\* and %LocalAppData%\import\. Remove these post-cleanup. |
| Legal/Policy Note | OFAC advisory 17-Feb-2022 names several wallet addresses associated with .architects; paying ransom may violate sanctions. Coordinate with counsel & cyber-insurance team. |

Fast-Reference Tool Kit

Emergency Patch-Pack (links to vendor advisories)

Recommended Scan/Cleanup Utilities

Use this resource as your immediate triage playbook; replace or update patches/tools as new vendor bulletins are released.