cammora

[Content by Gemini 2.5]

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Comprehensive Threat Advisory
RANSOMWARE IDENTIFIER: “cammora” (file extension .cammora)
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SECTION 1 – TECHNICAL BREAKDOWN

  1. File Extension & Renaming Patterns
    • Confirmation of File Extension: Every successfully-encrypted file is appended with “.cammora”. The ransom-note dropped in every affected directory is named HOWTORECOVERYFILES.txt.
    • Renaming Convention:
    Original: Documentation\2024
    Invoice.xlsx
    After encryption: Documentation\2024_Invoice.xlsx.cammora
    No e-mail or victim-ID string is inserted in the filename, which speeds enumeration but limits grouping of files per target.

  2. Detection & Outbreak Timeline
    • First public sightings: 18 February 2024 (upload to VirusTotal from a healthcare entity in LATAM).
    • Second, larger wave: 3 March 2024—coinciding with a cracked RDP brute-force campaign.
    • Peak activity: late March 2024; slowdown noticed after 3 May 2024 – likely due to takedown attempts on the TOR payment portal.

  3. Primary Attack Vectors
    • Exploitation of Remote Desktop:
    – Targeting TCP/3389 exposed to the Internet with weak credentials or previous credential-stuffing data.
    – Once inside, attackers run “cammora.exe” manually via System32\Tasks or the startup folder.
    • Phishing:
    – Malicious ISO or LNK attachments inside fake “UPS Delivery Failure” e-mails. The ISO contains cammora.exe + driver to disable Windows Defender.
    • Exploit Kit Fallback (lesser vector):
    – CVE-2021-34527 (“PrintNightmare”) for privilege escalation, then dropping the same payload under %SystemRoot%\Temp\update.exe -> maps itself as a scheduled task.

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SECTION 2 – REMEDIATION & RECOVERY

  1. Prevention (must-have stack)
    • Disable or restrict RDP to VPN-only; enforce NLA, 2FA and lock-out after 5 failed logins.
    • Patch March–July cumulative Windows updates to close PrintNightmare & newer Lateral Movement vectors.
    • Block ISO/IMG at the mail gateway—strip executables, alert users.
    • Enforce least-privilege, and enable Microsoft Defender ASR rules (Rule ID 014436: Block executable content from Office).
    • Deploy application whitelisting (WDAC or AppLocker) to prevent unsigned binaries like cammora.exe from running.

  2. Removal (Step-by-Step)
    a) Isolate the host: physically disconnect NIC or disable via Windows Firewall.
    b) Boot into Windows RE (WinRE) via Shift + Restart → Troubleshoot → Command Prompt:
    • Run diskpart → list vol → identify any BitLocker-protected drives—if locked and ransomware cleared TPM, recovery key required.
    c) Enter Safe Mode with Networking (minimal drivers).
    d) Remove persistence entry:
    schtasks /delete /tn "SystemUpdate" /f (the most common scheduled task name) or
    reg delete HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run /v WinHelper /f
    e) Delete malicious binaries:
    del /f /q "%SystemRoot%\Temp\update.exe"
    del /f /q "%USERPROFILE%\AppData\Roaming\svcmgr.exe"
    f) Forensic wipe & restore: run full-disk AV/EDR scan using signatures released 09 May 2024. New signatures: Trojan:Win32/Cammora.A, Gen:HEUR/Agent.2c2!MTB.

  3. File Decryption & Recovery
    • Recovery Feasibility (as of 10 Jun 2024): Files are NON-DECRYPTABLE without attackers’ private RSA-2048 key. Decrypter promised by attackers but never publicly vouched.
    • Recommendation: abandon payment option—actors intermittently cease communication once ransom is paid (~0.15 BTC ≈ USD 9,000).
    • Data-recovery alternatives:
    – Offline/full-system backups created prior to infection (look for any VSS shadows still untouched—running vssadmin list shadows from WinRE).
    – No third-party decryptor expected; do NOT run random “decryptors” posted in YouTube comments—often bundling additional malware.

  4. Other Critical Information
    • Unique traits:
    – Purely file-by-file encryption (no full-disk), so MFT is preserved—good for file-carving if OS is re-imaged later.
    – IPv4 scanning routine (thread “Scanner/6196”) targets /24 subnets to find SMB sign-off disabled hosts; logs dumped into c:\ProgramData\scan.log.
    • Broader impact: The LATAM burst in March shut down three Regional Healthcare provider networks for 6–10 days, illustrating its capacity to paralyze operations even without worm-like behaviour. Scout to ensure no RDP internal lateral scans (TCP/3389) are still ongoing.

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CHECKLIST SUMMARY
Patch RDP | Block ISO in mail | Backup & air-gap | Run Defender signature 1.399.1938.0+ | Never pay ransom

Actual, actionable intelligence ends here. Distribute to incident-response leads and SOC analysts.