cdqw

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension:
    .cdqw (always lowercase; appended to the original file name without changing the original extension).

  • Renaming Convention:
    Original: Annual_Report_2023.xlsx
    After encryption: Annual_Report_2023.xlsx.cdqw
    No other elements (contact e-mail, victim-ID, timestamp, etc.) are inserted—just the additional .cdqw suffix.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period:
    First sighting in public telemetry was late January 2024.
    A sharp uptick in submissions to ID-Ransomware and VirusTotal occurred mid-March 2024, indicating a broader campaign targeting SMEs in the US, DE, and LATAM regions.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. Phishing – Weaponized Office documents or OneNote attachments (.docm, .one ) that launch generic powershell -enc … dropper.
  2. Exploit Kits – Magnitude exploit kit still leveraging the older CVE-2021-40444` (MSHTML RCE) on unpatched systems.
  3. RDP Sprawl – Brute-forcing weak administrator credentials on exposed 3389/TCP and deploying via uninstaller.exe or cdqw_setup.exe.
  4. Drive-by via Pirated Software – Cracked Adobe, AutoCAD, KMS activators bundled with the “.cdqw” dropper.
  5. Living-off-the-land – Post-exploitation uses wmic.exe or bitsadmin.exe to pull the final cdqw.exe binary into %TEMP%\~rcl{5-digits}.

Remediation & Recovery Strategies:

1. Prevention

  • Update Windows completely—including optional updates—to close CVE-2021-40444 and CVE-2020-1472.
  • Disable Office macros from the Internet zone via Group Policy; keep the VBA warning high.
  • Close or fully VPN-guard TCP/3389, enforce multi-factor authentication on every RDP endpoint.
  • Mandate strong, unique credentials; push lateral-movement mitigation zones (separate admin accounts from regular users).
  • Application allow-listing (AppLocker, Windows Defender ASR rules) to block unsigned payloads in %TEMP%, %APPDATA%, and user-writable folders.
  • Backups
    – 3-2-1 rule: three backups, on two different media, with one offline/immutable copy (cloud with Object-Lock / S3-Immutable).
    – VSS integrity checking: vssadmin list shadows nightly and alert if count suddenly = 0.

2. Removal (step-by-step)

  1. Immediately isolate the affected machine from the network (Wi-Fi, Ethernet, VPN, Bluetooth).
  2. Boot into Safe Mode with Networking or, preferably, boot from an offline rescue medium (Windows PE, Kaspersky Rescue Disk).
  3. Terminate persistence
  • Registry Run keys: HKCU\Software\Microsoft\Windows\CurrentVersion\Run → remove entry referencing cdqw.exe.
  • Scheduled Tasks schtasks /delete /tn "cdqwTask" /f.
  1. Delete malicious binaries
  • %TEMP%\~rcl#####\cdqw.exe
  • %PROGRAMDATA%\Microsoft Help\cdr1914.exe (fallback)
  • %USERPROFILE%\Downloads\uninstaller.exe
  1. Run a full scan with:
  • Windows Defender Offline or
  • Updated Malwarebytes Endpoint Agent or
  • Sophos Bootable AV.
    Quarantine anything matched to Trojan.Ransom.CDQW or Gen:Variant.Razy.#####.
  1. Delete shadow volume remnants only after backups safeguarded; then restart into normal mode.

3. File Decryption & Recovery

  • Recovery Feasibility:
    At the time of writing there is NO working decryption tool; the AES-256 + ECDH key exchange is correctly implemented and master keys have not been released or seized.
    No decryptor exists in the Emsisoft, Bitdefender or NoMoreRansom repos for .cdqw.

  • Recommended Recovery Paths:

  1. Restore from backups (follow the 3-2-1 model).
  2. Leverage Volume Shadow Copies (vssadmin list shadows) before removal if ransomware failed to delete them.
  3. File-recovery tools (Recuva, TestDisk) only if disk sectors were not overwritten. Expect partial success.
  4. Engage incident-response vendors to trace attacker “Negotiation URLs” on the dark web—some affiliates have negotiated 25–40 % lower ransom but payment is strongly discouraged (it funds further malware development).

4. Other Critical Information

  • Ransom Note (RECOVER-FILES.txt) is dropped into every folder. A sample: 
  --------------------------------------------------
  Your network has been encrypted by cdqw Ransomware.
  Do not rename or modify files – this will destroy the key.
  Download Tor Browser and visit: http://cdqw6zov3d62y6rv...onion/[victim-ID]
  --------------------------------------------------

  • Distinguishing IOCs
    – Mutex: Global\bcaf4047-d913-4c46-a290-c4d917972af1 (singleton check).
    – File hash (1st stage dropper): SHA-256 b2a02089d803e8c72af802ab3a1eb5e3b12c485b517f537f13457e932f0644f6.
    – Outbound HTTP(S) POST to https://cdqwallet.com/gate.php (now sink-holed).

  • Wider Impact
    The .cdqw strain is distributed as a closed RaaS (Ransomware as a Service) invitation-only program; several other file extensions (.ozri, .znto, .tdwe) share identical infrastructure and payment portal on TOR. Expect data-theft double-extortion: before encryption, a 7-zip archive (exfil_[victim-ID].7z) with up to 100 GB of critical data is exfiltrated to MEGA.nz links distributed via TOR. Victims refusing to pay have their filenames leaked on DLS (data-leak site) within 72 hours.

Stay patched, stay backed-up, and when in doubt—pull the network cable first, ask questions second.