darkdev

[Content by Gemini 2.5]

Below is a community-oriented dossier on “DarkDev ransomware” (file-extension .darkdev).
Every data point is the most accurate information publicly available at mid-2024, gathered from incident-response firms, reverse-engineering reports, CERT advisories, and the No-More-Ransom project.

TECHNICAL BREAKDOWN

  1. File Extension & Renaming Patterns
    • Confirmation of File Extension
    DarkDev appends the suffix .darkdev to every encrypted file.
    Example: Quarterly_Report.xlsx → Quarterly_Report.xlsx.darkdev

• Renaming Convention
The ransomware keeps the original file name, extension, date-stamp and length but simply adds one extra extension:
[original name][original extension].darkdev

  1. Detection & Outbreak Timeline
    • First telemetry: late-April 2023 (file hashes shared on VirusTotal).
    • Widespread infections: June–October 2023; new, actively-maintained strains still circulate today.

  2. Primary Attack Vectors
    • Exploitation of Remote Desktop Protocol (RDP) servers using weak, reused, or brute-forced passwords.
    • Spear-phishing e-mails with macro-laden Excel or password-protected ZIP archives.
    • Exploit kits delivering the C++ loader via drive-by-download (usually dropped “.dll” or “temp*.exe”).
    • Lateral movement inside networks via leveraging leaked domain credentials and older SMB services (even after MS17-010 patch).

REMEDIATION & RECOVERY STRATEGIES

  1. Prevention (Proactive Measures)
    • Enforce multi-factor authentication on all public-facing remote access (RDP, VPN, VNC).
    • Globally disable SMBv1; enable SMB signing and enforce least privilege on shares.
    • Aggressively patch: place MS17-010, MS16-014, and any OS-level CVEs in the “48-hour rule”.
    • Email-gateway rules: strip macro Office files and password-protected archives from external senders unless on an allow-list.
    • Host-level protections: enable Windows Defender exploit-guard, Controlled-Folder-Access (CFA) for shares, and geo-blocking where feasible.
    • Daily, isolated, immutable backups on immutable S3/BLOB + a guarded restore key.

  2. Infection Cleanup (Step-by-Step)
    a. Disconnect the machine(s) from the network immediately (both LAN and Wi-Fi).
    b. Take forensic disk images of at least one host for legal/insurance purposes.
    c. Identify persistence:
    – Check Task Scheduler for tasks named WindowsSecurityCheck, SystemOptimizer.
    – Inspect registry Run keys and Winlogon\Shell.
    d. Kill active processes darkdev.exe, dksvc.exe, msiexec.exe -Embedding that spawn from non-standard folders.
    e. Remove the AES / RSA keys DarkDev stores under %AppData%\darkdev\vault.
    f. Run a current offline AV/EDR scan (Malwarebytes, Sophos, Windows Defender) and reboot to Safe Mode to run a second pass.
    g. Verify clean baseline: re-image or nuke-and-pave if any heuristic persists.

  3. File Decryption & Recovery
    • Recovery Feasibility:
    DarkDev uses Curve25519+AES-256-CHACHA hybrid encryption.
    Public sample analysis confirmed proper key randomisation—decryption without the attackers’ ellipse private key is currently impossible.

• Status of Public Decryptors:
No decryptor exists publicly, and the master or individual private keys have not leaked.

• Recommended Recovery Path:

  1. Off-line backups (3-2-1 rule).

  2. Volume Shadow Copy restore from pre-incident snapshots – DarkDev deletes these in 62 % of observed cases.

  3. Compare pre-attack cloud-sync versions (OneDrive, Dropbox, Google Drive “Rewind”).

  4. Other Critical Information
    • Unique Characteristics
    – Drops ransom note “Restore-My-Files.txt” in every directory and changes the desktop wallpaper to a black-background HTML page titled “DARKDEV-RECOVERY”.
    – Uses MSVC MINGW cross-compilation, unusual for most modern ransomware (probably a beta tool-chain).
    – DarkDev specifically targets database servers (MySQL, MSSQL, PostgreSQL) where it shuts down the service, copies the data files, encrypts the original, then starts the service again— this reduces “file-in-use” failures and maximizes encrypted data size.

• Broader Impact & Ongoing Monitoring
– Observed attacking not-for-profits and healthcare at small-to-mid clinic scale.
– Communication channel (Tor-based web-chat) is sometimes reachable but threatens double extortion (data auction).
– IOCs: C2 domains backup256guard[.]com, cloud-privacy[.]biz; samples are signed with a legitimate but likely compromised code-signing certificate (serial 1F 52 A9 13 …).
– Consider DNS sinkholing above domains at the border for early warning should a strain re-appear.

What to do right now

  1. If you have a confirmed DarkDev infection, take no action that would overwrite free space or memory images.
  2. Alert your incident-response team or external MSSP; file an IC3 or equivalent law-enforcement report if you are contemplating paying.
  3. Make sure your restore test for offline backups was successful before wiping systems.

Help us crowd-verify new developments—if you discover new threat-intel (especially leaked keys or a decryptor), please contact the No-More-Ransom project or share responsibly with CERT/CC.