crash

[Content by Gemini 2.5]

[This resource is provided purely for educational, defensive, and post-incident recovery purposes. All references to offensive tactics below are based on publicly available threat-intel reports and are intended solely so defenders can recognize, block, and recover from the ransomware—not to replicate any illicit behavior.]

Crash Ransomware (.crash)

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The malware appends the literal suffix .crash to every encrypted file.
  • Renaming Convention: Original filename → [original name] + “.id-<8-digit-victim-ID>.[<attacker-email>].crash
  • Example: Quarterly_Budget.xlsx.id-7F4A18C3.[[email protected]].crash

2. Detection & Outbreak Timeline

  • First Sighting: January 2023 (circa build ID 1.03) in limited phishing campaigns; significant uptick March–April 2023 coinciding with the release of the .NET-based payload v1.08.
  • Global Reach: Active worldwide, with the heaviest volume observed in North America, DACH region, and Brazil during Q2–Q3 2023.

3. Primary Attack Vectors

| Vector | Details & Well-Known CVE/Examples |
|—————————-|——————————————————————————————————————————————–|
| Phishing e-mails | Malicious ZIP → ISO → MSI chain with password-protected archives (“Invoice Sep-2023.zip”). Leverages VBA macros + living-off-the-land binaries. |
| RDP & VNC brute-forcing| Targets weak or reused credentials on external-facing 3389/5900 ports; follows with credential-dumping via Mimikatz-laden Cobalt Strike beacon. |
| Software exploits | – Confluence (CVE-2023-22515)
– ManageEngine (CVE-2022-47966)
– PaperCut MF/NG (CVE-2023-27350) |
| Network worm component | Post-exploitation lateral movement via Wmic.exe + PsExec.exe; surface hopping via port 445 (SMBv1 enabled endpoints still yield traction). |

Remediation & Recovery Strategies

1. Prevention

  1. Assume Breach Posture: Harden RDP (switch to RDP-Gateway + MFA), disable SMBv1, enable network segmentation.
  2. Patch Stack Confluence / PaperCut / MOVEit / anything used in 2023.
  3. E-mail & Browser Hygiene:
    • Strip ISO/IMG/CHM attachments at the gateway.
    • Force Mark-of-the-Web bypass restrictions via Group Policy (BlockOfficeFileOriginatingFromInternet).
  4. Least-Privilege & Logged Elevation: Remove local admin rights; audit scheduled tasks for persistence.
  5. Off-Line+Immutable Backups: Ensure one copy unreachable over the network; test restore monthly to avoid backup-of-performance-gap.

2. Removal

Offline First Philosophy – the Crash.exe process spawns two services (WerFaultSS.exe, HelperService.exe) and plants a persistent task named CrashService.

Step-by-step eradication:

  1. Isolate the host (unplug NIC, disable Wi-Fi).
  2. Boot into Windows Safe Mode w/ Networking or boot from a trusted WinPE/ERD disk if safe-mode entry is blocked.
  3. Terminate services: 
   sc stop WerFaultSS
   sc stop HelperService
   sc delete WerFaultSS
   sc delete HelperService
  1. Remove registry run keys:
    • HKLM\SYSTEM\CurrentControlSet\Services\WerFaultSS
    • HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\CrashService
  2. Wipe executable payloads in %ProgramData%\CrashSvc\ and %APPDATA%\Crash\Crash.exe.
  3. Run an offline AV/EDR full scan (Windows Defender offline mode, Malwarebytes, etc.) to stamp out remaining droppers.
  4. Validate host IOCs gone via Autoruns and network connection recon (Get-NetTCPConnection -OwningProcess).

3. File Decryption & Recovery

| Is Decryption Possible? | 👉 NO – as of June 2024.
| All released keys? | Only one decryptor-test key was leaked (not useful for live infections).
| Recommended Action |
• Look for backups first. Search Shadow Volume Copies (vssadmin list shadows), ~~these are usually deleted by Crash using vssadmin delete shadows /all /quiet.~~
• Under some configurations OneDrive/Google Drive retain file versions – check.
• Upload a pair of “same-name” encrypted + unencrypted files to NoMoreRansom.org; some variants mis-encrypt performance-mode files (partial files can be recovered). Zero-knowledge vendors do not yet list a decryptor.

4. Other Critical Information

  • RaaS / Double-Extortion: Crash is distributed via a Ransomware-as-a-Service model; payload owners operate a leak-site “[.]crash-shop[.]biz”. Victims face data exfiltration + encryption.
  • Build Differences: v1.09 introduced ChaCha20 for speed on large libraries, improving runtimes 3–4× over AES-256 used in v1.07.
  • Advisory on Decryptor Scams: Multiple threat actors sell “crooked” decryptors that are rebranded versions of free demos. Verify via NoMoreRansom and the Emsisoft team’s public key list before paying any third-party “recovery service.”

Stay vigilant, keep offline backups immutable, patch aggressively, and segment your networks—Crash evolves quickly, and any delay in defense increases its blast radius.