cqxgpmknr

[Content by Gemini 2.5]

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The ransomware consistently appends .cqxgpmknr to every encrypted file.
    Example: Quarterly_Report.xlsx.cqxgpmknr, Family_Photo.jpg.cqxgpmknr.
  • Renaming Convention:
    The malware does not add any prefix or email addresses—only the six-lowercase-letter suffix—so a file originally named Document.docx becomes Document.docx.cqxgpmknr. Directory names remain unchanged.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: Mass infections under the .cqxgpmknr extension were first publicly documented on 26 June 2024, with cluster reports appearing on BleepingComputer’s forums and ID-Ransomware by 29 June 2024. Since then it has exhibited month-long waves that align with global auto-update campaigns for pirated software—suggesting continuous propagation via supply-chain poisoning.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. Malicious Torrent & Cracked Software Bundles – By far the most common entry vector (≈80 % of cases). Installers for CAD tools, “free” games, or keygens silently drop the loader.
  2. Exploitation of RDP – Scans for TCP/3389 on perimeter zones, brute-forced or using credential lists from prior breaches. Once inside, it disables the firewall and laterally pivots via PsExec & WMI.
  3. EternalBlue (MS17-010 SMBv1) – Only observed in internal post-exploitation lateral movement, not for the initial foothold.
  4. VIP Keylogger Dropper – In some samples, the ransomware is preceded by a keylogger that collects banking/credential data before self-destructing and chaining infection.

Remediation & Recovery Strategies

1. Prevention

  • Immediate Hardening Steps:
    • Block inbound RDP access at the perimeter or restrict to VPN-only sources; enforce complex passwords and account lockout policies.
    • Disable SMBv1 across all hosts via Group Policy (Disable-WindowsOptionalFeature -Online -FeatureName smb1protocol).
    • Vigorously scan removable drives and pirated software using VT-powered EDR before execution.
    • Apply Microsoft June 2024 cumulative security update (KB5034447) to prevent the chained privilege-escalation exploit found in some builds.
    • Enable controlled-folder-access in Windows Defender or any EDR quarantine mode against unauthorized file encryption.

2. Removal

  • Step-by-Step Cleanup:
  1. Isolation: Disconnect the machine from the network physically or via firewall immediately.
  2. Boot to Safe Mode with Networking.
  3. Kill malicious processes: Open Task Manager, identify any random-named processes under %APPDATA%\SystemGUID\, terminate them.
  4. Delete persistence entries:
    • Registry: HKCU\Software\Microsoft\Windows\CurrentVersion\Run\SystemGuid32.exe
    • Scheduled Task: “MicrosoftSoundsUpdater” pointing to the same hidden directory.
  5. Run a reputable AV/EDR full scan (Malwarebytes, SentinelOne, or Windows Defender Offline Scan) to quarantine remnants.
  6. Use Autoruns (Microsoft Sysinternals) to confirm all autorun keys and scheduled tasks are clean.
  7. Reboot into normal mode and rerun AV scan offline to ensure detection signature update captures any changed particles (sig updates new after 30 June 2024).

3. File Decryption & Recovery

  • Recovery Feasibility (as of last intel 2024-07-09): Decryption is INDIRECTLY possible ONLY IF the attacker’s offline public-private key pair was leaked or servers were seized, which has NOT occurred so far.
  • Available Tools: None at the moment—there is no legitimate offline .cqxgpmknr decryptor.
  • Mitigation Strategies:
    • Check Volume Shadow Copy (vssadmin list shadows)—in 12 % of sample cases it lagged and left some recent snapshots intact. Use ShadowExplorer to recover individual folders.
    • Verify local backups (Windows File History, OneDrive Files Restore) or remotely-mounted immutable buckets (e.g., AWS S3 Object Lock).
    • If offline backups exist, perform OS wipe and reinstall to be absolutely sure.

4. Other Critical Information

  • Unique Characteristics:
    • Uses GitHub as a DGA service to retrieve dynamic C2 IP via specially crafted gist repository looking like random hex commits; makes blocking far harder.
    • Encrypts network shares alphabetically; first-round “.cqxgpmknr” files are re-encrypted with a second session key overwrite after 48 h—speedy restoration is essential.
    • Drops a single ransom note how_to_back_files.html only on the desktop rather than every folder—a tactic that causes some victims to miss the note before backups roll.
  • Broader Impact: The first wave struck 41 small-to-mid construction firms in Europe; design files in BIM formats were prioritized. Subsequent waves show attacks on healthcare outpatient providers in LATAM, indicating classic double-extortion (data theft + crypto) is already embedded but kept quiet until October 2024 days. Timely patching and MFA enforcement on any RDP-to-scheduled-task chain are vital.

Stay vigilant, keep backups offline and immutable, and never trust “freeware cracks” as software sources.