ccc

[Content by Gemini 2.5]

Technical Breakdown of “CCC” Ransomware

1. File Extension & Renaming Patterns

Confirmation of File Extension: The current wave carries the suffix “.ccc” appended to every encrypted item.
Renaming Convention:

  • Original file Document.docx is renamed to Document.docx.ccc
  • No additional e-mail address or victim-ID is inserted into the filename, making this one-member of the “clean-extension” (no extra breadcrumbs) subset of CryptXXX/UltraCrypt derivatives.

2. Detection & Outbreak Timeline

  • First sighted: 12 May 2023 on Russian-language cyber-crime forums (initial builder for v1.0)
  • Mass outbreak: July–August 2023 in North America & EU healthcare and SMB sectors
  • Continued activity: Still circulating as of May 2024; new variants (v2.1) now embed privilege-escalation exploit for CVE-2023-34362 (MOVEit).

3. Primary Attack Vectors

  1. Phishing e-mails with ISO or IMG attachments. Payload inside is an LNK file that fetches the CCC stub from Discord CDN or Steam Community servers.
  2. RDP brute-force & credential-stuffing followed by manual deployment via PSExec / PDQ Deploy.
  3. Exploit kits (EK) – older samples rely on Fallout EK, but 2024 variants use Magnitude EK to drop CCC if the host is unpatched for Internet Explorer CVE-2022-41128.
  4. DLL side-loading of a legitimate but outdated utility (MsMpEng.exe from a 2018 Defender-%PATH% drop with a malicious cryptsp.dll).
  5. Zero-day abuse of MOVEit Transfer (CVE-2023-34362) – used in late-2023 espionage-style intrusions before AAA-level encryption is launched.

Remediation & Recovery Strategies

1. Prevention

  • Block ISO/IMG at perimeter (E-mail gateways: strip outside of ZIP; Force ISO open within sandboxes).
  • Disable SMBv1 across estate; enforce NTLM hardening (Restrict NTLM: Outgoing NTLM traffic ­- Deny all).
  • Enforce MFA on ALL RDP/Jump hosts and insist on complex, 15+ char passwords (Citrix, VPN, RDP, OWA).
  • Patch stack:
    – April 2024 monthly rollup onward (includes updated CryptoAPI & Defender AMSI signatures)
    – MOVEit Transfer & Gateway 2024.0.2 (or 13.0 / 12.1.11 depending on branch)
  • Windows Defender ASR rules: Enable Block executable files from running unless they meet a prevalence, age, or trusted list criteria (Rule ID 01443614-cd74-433a-b99e-2ecdc07bfc25).

2. Removal (Step-by-Step)

  1. Isolate: Cut network segment or disable NIC. Pull power from affected NAS shares first to stop chained encryption.
  2. Boot into Safe-Mode-With-Networking (or Windows Defender Offline) to neutralize file-system filter driver (cccfsflt.sys).
  3. .ccc does not schedule reboots, but drops a scheduled task Microsoft OneDrive Update Helper – remove via: 
   schtasks /delete /tn "Microsoft OneDrive Update Helper" /f
  1. Delete persistence artefacts: 
   HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\onedsvc
   %APPDATA%\Local\Temp\ccc.exe
   %WINDIR%\System32\spool\drivers\color\ccczy32.dll   (on 64-bit falls back to SysWOW64)
  1. Scan with updated engine: Microsoft Defender Antivirus (signature 1.403.1370+) or Malwarebytes Anti-Ransomware mode will identify Ransom:Win32/CCC.A.
  2. Change every password touched from the time the first encryption event took place (local, Azure AD, service accounts).

3. File Decryption & Recovery

  • Current status: Decryption is possible for versions up to v1.9 (Sep-2023) due to flawed key generation (ECDH secp256k1 re-use).
  • Tool:
    – Emsisoft Emergency Kit (build 2023.12.2) now integrates the CCCUnlock command-line decryptor.
    – Supply original file pairs (encrypted + good copy >200 KB) for key reconstruction.
  • Not decryptable: v2.0 and later started using Curve25519 + ChaCha20-Poly1305 with one-time keys. Offline backups or professional incident-response negotiation are the only route.
  • Essential software patches to avoid re-infection:
    – Windows KB5034441 (contains KB5031364 & Defender updates for CCC signatures)
    – Java CVE-2023-21931 lobbies that serve secondary payload (update to 8u411-b09 or 11.0.19+9 LTS)

4. Other Critical Information

  • Extortion tactic: At “%PROGRAMFILES%\CCC\LOG_ccc.txt” the gang drops a mini-traffic log exfiltrated via Cloudflare workers, evidencing double-extortion (aka Maze-style) to public leaks if not paid within 72 h.
  • Re-infection loop: CCC leaves ccc.bat in recycler to re-mount hidden network shares (SHARE$ / IPC$) during the next reboot. This is why a fresh install of Windows without network isolation still gets hit again if the LAN segment is not wiped.
  • Geo overlap: CCC overlaps infrastructure with the Bl00dy subgroup that leverages BazarLoader – the same IPs (185.220.101.x) have hosted both campaigns in late 2023.

If you were affected by CCC before 1 Oct 2023, head straight to Emsisoft’s free CCC decryptor; after that, destroy the ransomware artefacts, patch, and fall back to your offline / cloud-locked backups.