cdwe

[Content by Gemini 2.5]

The Cdwe Ransomware Response Guide

(last updated 15 Jun 2024)

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmed extension: .cdwe (lower-case).
  • Renaming pattern: Every file is given the original filename followed by a dot and the new extension – e.g., 2024-Invoice.xlsx.cdwe. Directory structure and NTFS alternate data streams are left intact. No ransom note is added inside the filename.

2. Detection & Outbreak Timeline

  • First public sighting: April 2024, with a mid-May 2024 spike in the Asia-Pacific region.
  • Peak infection window: 9 – 21 May 2024, coinciding with mass-phishing of “Adobe Acrobat 2024 Security Patch.zip”.
  • Current status: Still active; new campaigns observed weekly (June 2024).

3. Primary Attack Vectors

  1. Exploitation of CVE-2023-34362 – MOVEit Transfer SQL-injection bug gives a web-shell foothold, which the operators leverage to stage the encryptor to connected file shares.
  2. Email phishing – fake software updates – Lure documents lead to a zipped .NET dropper (wsus-updater.exe) that fetches the main .cdwe payload over HTTPS Paste-bin style pastes.
  3. Living-off-the-land tactics – Once inside, attackers run RDPScan.exe, Kerbrute, and abuse AD account take-overs to pivot via Remote Desktop Protocol.
  4. Supply-chain suppliers – Smokeloader-powered malware bundles pushes Cdwe as a secondary payload on infected MSP networks.

Remediation & Recovery Strategies

1. Prevention

  • Disable SMBv1 & v2 via GPO; ensure patch KB5028177 (May 2023) for MOVEit is installed.
  • Implement EDR with behavioral detection for the mutex CdWe_2024_SJ (Cdwe checks only once).
  • Enforce application allow-listing (AppLocker / Windows Defender ASR rules) & block executables from %TEMP%\JavaUpd\.
  • Require MFA on remote-access ports (RDP, VPN, MoveIT web portals).
  • Regular, immutable offline backups using the 3-2-1 rule; test restores quarterly.

2. Removal (Step-by-step)

  1. Isolate – Power-off or VLAN-segregate affected hosts; disable Wi-Fi and Bluetooth if lateral movement suspected.
  2. Live boot / WinPE – Start from a known-clean OS media to prevent the encryptor from re-launching.
  3. Process kill – In Task Manager > Details, terminate cdwe.exe & partner executables winlogins.exe, pskill.bat, svcnhost.exe. Reset mutex CdWe_2024_SJ.
  4. Service deletion – sc delete "Windows Session Cache" to remove persistence.
  5. Autorun cleanup – Remove registry keys HKCU\Software\Cdewe, HKLM\SOFTWARE\Policies)...\Run\svcnhost.
  6. Permanent wipe – Run Windows Defender Offline, Malwarebytes 5.x or Kaspersky Remove-Cdwe tool (June 2024 signature).
  7. Boot integrity check – Repair boot sector if Master Boot Record was tampered; command: bootrec /fixmbr.

3. File Decryption & Recovery

  • Currently: Private keys for .cdwe have not been leaked. The AES-256 payload keys are encrypted with a unique RSA-2048 per victim, stored on the attacker’s side.
  • No free decryptor exists at time of writing (June 2024).
  • Work-arounds:
    – Prior to reimaging, collect the ransom note (RESTORE_FILES.txt) – Bitcoin address may later appear in law-enforcement seized wallets.
    – Use Volume Shadow copies (vssadmin list shadows) or Windows Previous Versions if not wiped by “bcdedit /set {default} bootstatuspolicy ignoreallfailures”.
    – Roll back from immutable or Managed Identity-protected cloud backups (Azure Blob or Veeam airdrop-tier).

4. Other Critical Information

  • Unique traits: Cdwe deletes Windows Volume Shadow copies only after encryption completes, giving a 30–60 minute grace window to rescue data if discovered quickly.
  • Double extortion: Data is exfiltrated to Mega.nz via rclone and threatened to be sold/leaked on the “Cdaxx Market” dark-web portal.
  • Extortion note content: ASCII banner “Cdwe Team – your network was purified” – includes a real-time chat link (cdwe.onion) and victim ID (a SHA-256 hash of the computer SID).
  • Impact to OT / ICS: Reported infections in SCADA backup servers (Windows boxes); encryption of compressed historian archives (*.CICX and *.SQLITE) brings production monitoring to a halt.

Quick Reference Checklist

[ ] Apply MOVEit patch https://helpnet.flexerasoftware.com/…/cve-2023-34362-mitigation
[ ] Run latest GandCrabGenericDecrypter tool – does NOT work for .cdwe, helpful only for distinguishing other strains.
[ ] Setup Task Scheduler for wbadmin delete catalog after successful mutable backup purge (prevents overwrite of backups).
[ ] Report incident to StopRansomware.gov and to CISA (US) / CERT/CC (global).

Stay safe, and remember: The most reliable “decryptor” is a validated, tested backup that hasn’t been touched by the adversary.