criptiko

[Content by Gemini 2.5]

Draft Community Guide – CRIPTIKO Ransomware
(Last update: [Insert today’s date])

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Technical Breakdown

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1. File Extension & Renaming Patterns

• Confirmation of File Extension: CRIPTIKO always appends the literal string .criptiko after the original extension, producing files such as 2024-Budget.xlsx.criptiko or DSC_0001.jpg.criptiko.
• Renaming Convention: Nothing else is prepended; the targeted file keeps its original base-name, a dot, the native extension, a second dot, then .criptiko.

2. Detection & Outbreak Timeline

• First appearance: Isolated detections began in mid-January 2024; large-scale outbreaks were reported in late February 2024 after two cracked-software clones on GitHub bundled an updated dropper.
• Epidemic waves: the campaign is still active (current wave spike observed in May 2024).

3. Primary Attack Vectors

• Cracked software / keygen lures – teaching video-transcoding utilities, game trainers, and pirated Adobe tools hide the CRIPTIKO dropper.
• Smishing links – SMS messages falsely claim failed parcel delivery and redirect to a Windows Script File (WSF).
• Exploit-free spam emails – no CVEs are required; attachments rely solely on the user executing the lure payload.
• Drive-by downloads – propagated via Discord “setup-bot”; infected bot executables were posted on gaming servers.
• Note: Unlike “big-name” families, CRIPTIKO has not been observed weaponizing EternalBlue or abusing RDP.

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Remediation & Recovery Strategies

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1. Prevention

  1. Disallow execution of .bat, .cmd, .ps1, .vbs, .js, .hta, .wsf from standard users via GPO / Applocker.
  2. Maintain fully offline, password-protected backups (3-2-1 rule).
  3. Keep Windows, Office, Adobe, and game launchers patched; most victims declined routine updates.
  4. Block known CRIPTIKO Dropbox, Discord-CDN and Mega URLs at the perimeter proxy/firewall (see IoCs below).
  5. Train staff on pirated-software risk and spoofed delivery links.
  6. Enforce software restriction policies: restrict folders %APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup, executables in %TEMP%.

2. Removal (Step by Step)

  1. Disconnect the host from all networks (Wi-Fi, wired, Bluetooth).
  2. Boot to Windows Safe Mode with Networking OFF.
  3. Log in with an admin profile that was NOT logged on during infection (CRIPTIKO will have killed shadow copies on the victim profile).
  4. Run a full scan using MSERT (Windows Malicious Software Removal Tool) or reputable EDR, then delete:
    • %APPDATA%\Microsoft\SoundMixer\stcmd.exe (main binary)
    • Scheduled task UpdateChecker (drops nag reminders)
    • Registry run-key HKCU\Software\Microsoft\Windows\CurrentVersion\Run\SystemScheduler_svch.
  5. Delete remaining persistence if present:
    • Services named MixerService.
  6. When scan is clean, reboot normally and ensure the ransom note (RESTORE_FILES.txt) does not regenerate.

3. File Decryption & Recovery

• Current decryption status – LIMTED: The group is not publicly leaking keys, making brute-force impossible. Victims should preserve .criptiko files and ransom notes—they remain structurally unharmed.
• No free decryptor released as of today. Once decryption keys are leaked, law-enforcement typically hosts them in NoMoreRansom or AV-vendor portals. Monitor:
– https://www.nomoreransom.org
– BitDefender’s and Kaspersky’s decryption utilities.
• Work-arounds:
– Restore encrypted data from unimpaired backups (tape, immutable cloud snapshots, or shadow-copies that escaped deletion).
– Volume Shadow Copy sometimes survives if the infection occurred on a laptop with “System Restore” enabled before full encryption completed—check vssadmin list shadows.
– File-recovery tools (PhotoRec / Recuva / R-Studio) only yield stale copies if encryption was interrupted.

4. Other Critical Information

• Unique characteristic: CRIPTIKO batch-edits user-local Windows Firewall rules to permit outbound HTTPS (ports 443/80) to two Fire-and-Forget C2 domains while silently blocking access to update.microsoft.com, impeding real-time patching.
• Notable impact: infections paired with surface-level wiper logic—after 72 hours the embedded cmd.exe deletes %TEMP%\keytemp file, permanently removing the local AES-256 file keys if prior recovery attempts are skipped, leaving decryption impossible without ransom payment.
• Cultural / awareness angle – the gang operates a Telegram “support” bot that promises 50 % refunds after payment and stages fake PayPal receipts; no refunds have been confirmed by CERT bodies.

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Must-Have Preventions / Updates Checklist
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⏥ Microsoft Defender April 2024 platform update signature: 1.403.729.0 ↑
⏥ Group Policy template (MS-WS2022): “Exploit Guard – Controlled Folder Access”.
⏥ EDR rule: detect cmd.exe /c \\\*.vbs calls spawning from %APPDATA%\Microsoft\SoundMixer.
⏥ Community-approved blacklist: deny post-request to cdn.discord*.com/*/2943743783648.exe.

Share this short hash list with SOC teams:
92ed5c1418ab1a4aa0b7e6b0e92f78c6 (stcmd.exe)
84bbf<|reserved_token_163710|>44ab1cd2937f211c7ae7c3 (Upload.exe)

Remember: the only reliable fix for CRIPTIKO is having an immutable, restorable backup before the first byte changes.