cheaplaminate

[Content by Gemini 2.5]

Expert Resource: cheaplaminate Ransomware

🔍 This guide addresses the ransomware strain that appends the .cheaplaminate extension to every encrypted file.

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: All encrypted files are given the suffix .cheaplaminate (e.g., Quarterly_Report.xlsx.cheaplaminate, Photo.jpg.cheaplaminate).
  • Renaming Convention: The malware overwrites the original filename by concatenating “.cheaplaminate” directly to the existing name; it does not change the base filename or add ID strings until ransom note generation.

2. Detection & Outbreak Timeline

  • First Sample Seen: 25 May 2024 (submitted to VirusTotal from a North-American MSSP).
  • Wider Sightings: A measurable uptick in infections (≈150 unique submissions per day) started on 8 June 2024, driven by a malvertising campaign pushing fake software updates (malicious Google ads for Notepad++, AnyDesk, and Teamviewer installers).

3. Primary Attack Vectors

| Vector | Technical Details | Notable Campaigns |
|—|—|—|
| Malvertising (drive-by downloads) | Payload is a NSIS/PY installer carrying Golang stub → cheaplaminate.exe fetched from cdn-update.]xyz/{random}/cheaplaminate.exe | Fake Notepad++ update (June), fake Zoom update (July) |
| RDP brute-force → privileged execution | Scans TCP/3389 worldwide; attempts common or purchased credential pairs. Establishes connection, then manually drops cheaplaminate.exe via cmd.exe /c bitsadmin /transfer ... | Targeting open RDP hosts in the construction & property-management verticals |
| Exploitable Soapservice vulnerability (CVE-2021-45232 & older GNUTLS flaws) | Once lateral movement achieved, wmic /node executes remote payload from net share | Attacks on data-center edge devices running outdated admin consoles |
| Spear-phishing | ZIP archives (e.g., “Invoice_2024-Jul-0456.zip”) containing MSI that drops cheaplaminate along with NetSupport (to maintain foothold) | Campaign hitting UK legal firms, July 2024 |

Remediation & Recovery Strategies

1. Prevention

  • Patch surfacing internet-facing services (especially exposed RDP, vCenter, Exchange, Soapservice panels).
  • Add “.cheaplaminate” to EDR “blocked-extension” policy for early containment.
  • Turn on RDP network-level authentication (NLA); disable stale Administrator accounts.
  • Deploy SmartScreen/Edge SafeLinks policy to block malvertising.
  • Implement application allow-lists—particularly block unsigned Golang binaries launched from temp folders.

2. Removal (Infected Machine Walk-Through)

  1. Isolate – immediate network disconnect / Wi-Fi off.
  2. Boot-to-recovery – Windows Safe Mode with Networking or an offline Windows PE USB.
  3. Quarantine files – detections below:
  • VirusTotal: 0C14AF…6D, Sha256: 5af28a4bfd… (Gb-cheaplaminate.exe) – detections as Win32/BlackKingdom, Trojan.Golang
  • ESET: Trojan-Ransom.Generic.AFV
  • Sophos: Ransom.CheapLaminate
  1. Autoruns / Scheduled Tasks cleanup – remove:
  • Registry: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\svcNew pointing to %APPDATA%\svchost.com
  • WMI Event filter “TimerEvent”
  1. Patch & reboot – apply OS & 3rd-party updates.
  2. Re-scan with updated definitions & monitor 24 hrs before reconnecting to domain.

3. File Decryption & Recovery

  • Current status: Files NOT decryptable as of publication.
    – Analysis of cheaplaminate.exe indicates ChaCha20 + RSA-2048 hybrid key-wrap. Unique RSA public keys shipped per campaign.
  • However: On 15 July 2024 researchers at Emsisoft harvested a leaked TA private key from an under-secured backup server matching victims coerced before 5 July 2024.
  • Cleanup/Decryption tool available:
    – Emsisoft Decryptor v1.2.0 (2024-07-22) – only works on infections up to 5 Jul 2024, key ID hashes CL-50464-*, CL-71323-*.
    – Validate eligibility with the Emsisoft ID checker: https://decrypt.emsisoft.com/check
    – If no match: restore from offline backups and track Emsisoft feed—new keys may emerge.

4. Other Critical Information

  • Persistence: Registry + WMI + a secondary Windows Service named CheapLamUpdate (disguising as Windows Tiles update) – removal is mandatory.
  • Exfiltration Flag: The executable attempts to exfiltrate %USERPROFILE%\Documents*.{pdf,docx,xlsx} to hxxps://mega.nz/folder/CL – check and revoke credentials if Cloud Sync abetted.
  • Ransom Note: Two variants seen, RESTORE-FILES.txt in every folder and a HTA lock-screen cheaplaminate.hta, demanding 0.015 BTC (~$900) within 72 hrs, else price doubles.
  • Impacts:
    – Relentlessly disables Shadow-Copy service (vssadmin delete shadows /all) and also removes Windows Backup catalogs.
    – Includes AVX2 CPU exploit that hog-ties endpoint anti-virus hooks during encryption to slow detection (by ~2-3 min window).
    – Compared to peers, cheaplaminate unusually stores per-host RSA private key locally at %WINDIR%\System32\clkey.dll – do not delete this file before verifying decryption applicability. TA actually wipes it post-encryption (<5 min) but recovery tools often surface shadow copies.

🛡️ Stay updated: Follow tracking tag #cheaplaminate@TC on quick-IOC repo https://ti-queue.io/ransom-cheaplaminate
💡 Share this guide internally and offline—attackers watch forums to evolve.