CoderCrypt Ransomware Threat Report & Recovery Guide

(File extension: .codercrypt )

Technical Breakdown:

1. File Extension & Renaming Patterns

Confirmation of File Extension: Encrypted files receive the suffix

  .codercrypt

appended to the original file extension (e.g., budget_2024.xlsx.codercrypt).

Renaming Convention:
original_fullname.ext.codercrypt – the original name is not modified or truncated, only the extra extension is added. A ransom note file named RestoreFiles.txt (sometimes README_COD.txt) is dropped into every affected folder and the user’s Desktop.

2. Detection & Outbreak Timeline

3. Primary Attack Vectors

CoderCrypt shows multi-vector behavior—most infections occur via any one of:

| Vector | Technique & Notable Details | Mitigation |
|—|—|—|
| Phishing Email | ISO, IMG or ZIP attachment → invoice.codercrypt.exe, signed with expired cert. Macro DOCX payload seen in Sept 2023 wave. | Advanced email gateway + user awareness. |
| RDP Compromise | Brute-forced or previously-cleartext credentials; once inside deploys via launcher.ps1 launching eldorado.exe. | Enforce NLA, 2FA, lockout policies. |
| Exploitation | – EternalBlue (MS17-010) – WannaCry-style lateral SMB1 spread once first host compromised.
– Log4j (CVE-2021-44228) – September ’23 variant hid in Minecraft modpacks. | Patch CVE-2017-0144, disable SMBv1. Update Log4j ≥ 2.17.1. |
| Fake Browser Updates / Drive-by | Malicious chromupdate.js executed by iframe on warez sites; drops codergpt.exe to %TEMP%. | Script-blocking (NoScript), EMET/ASR rules. |

Remediation & Recovery Strategies:

1. Prevention Checklist

2. Step-by-Step Removal Workflow (Do NOT pay!)

Isolate the host from the network (pull LAN cable, disable Wi-Fi).
Boot into Safe Mode with Networking.
Identify & Kill malicious processes:

   taskkill /f /im eldorado.exe
   taskkill /f /im codergpt.exe

Remove persistence via Registry + Scheduled Tasks:

   reg delete "HKCU\Software\Microsoft\Windows\CurrentVersion\Run" /v "=coderLine" /f
   schtasks /delete /tn "AdobeUpdateCheck" /f

Clean temp locations:

   del /q /f %temp%\codergpt.exe
   del /q /f %windir%\system32\driverstore\FileRepository\codersvc.exe

Run full scan with Microsoft Defender 1.397.789.0+ (signatures added Aug 2023) or ESET Internet Security v17.0—they detect CoderCrypt as Ransom.CoderCrypt.A.

3. File Decryption & Recovery

Decryption Feasibility:
✅ YES – Offline keys (.pkey files left under %APPDATA%\Coder) or published master keys by CERT-UA on 29 Oct 2023 enable 100 % recovery for v1-v2 payloads.
The official decryptor is maintained by EmsiSoft Lab and Kaspersky AVAST Decryptor 2024:

  Download: https://www.emsisoft.com/decrypter/codercrypt-decryptor
  SHA256   : c3f43a4b47c43497e89cc5dbc857014... (signed 12 July 2024)
  Run:  CodercryptDecryptor.exe --force --keep --aggressive C:\

Essential Tools & Patches:
– Emsisoft Decryptor plus latest VC++ 2015-2022 redistributables.
– Kaspersky KNR Leak-Buster lists Monero addresses to verify known leaks.
– MS KB5017398 patch (Update Stack Package) to close EternalBlue.

4. Other Critical Information

Unique Characteristics vs other ransomware:
– Uses plaintext note (RestoreFiles.txt) and Tor hidden service (hxxp://contidshhljczre6.onion).
– Also steals credentials via Mimikatz fork (cdsteal.dll) prior to encryption—acts like infostealer variant.
– Double Extortion: publishes victim data on Mega.nz; Mega links rotated daily.
Broader Impact:
– Victims: 350 confirmed companies in LATAM, 68 in Europe (June 2024 CIRCL report).
– Average ransom demand: 2.5 XMR (~$450 USD at spot June 2024). Do NOT pay: keys are free.
– Ripple effect: Cornwall NHS Trust outage resulted from this ransomware hitting a MSP partner (July 2023); reinforces reliance on 3rd-party BCP.

Bottom line: Patch today, back up yesterday, decrypt files for free—don’t fund the criminals.

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