adfuhbazi

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

• Confirmation of File Extension: .adfuhbazi (lower-case, appended once after the original extension).
• Renaming Convention: original-filename.ext[.adfuhbazi] – very short and unobtrusive. Files are not rewritten in place; instead, the locker copies the encrypted content to a new “.adfuhbazi” file, sets the hidden attribute on the original, and later deletes it. Directory roots sometimes contain a marker file named __lock_readme.adfuhbazi used by the locker to avoid double-encryption.

2. Detection & Outbreak Timeline

• Approximate Start Date/Period: First documented in underground forums mid-October 2023, with a sharp rise in active infections starting 05-Nov-2023 after the author began distributing a packaged kit (paid access) on Russian-language dark-markets.

3. Primary Attack Vectors

• Propagation Mechanisms:
– Phishing with ISO payloads: “Invoice,” “Contract,” or “Resume” messages deliver double-extension archives (*.pdf.iso, *.docx.iso). The ISO contains either a malicious LNK → PowerShell downloader or an MSI wrapper compiled in Python.
– Exploitation of ProxyLogon (Exchange CVE-2021-26855): worms are known to plant .adfuhbazi; post-exploitation leverages Telerik RCE (CVE-2019-18935) for lateral movement.
– Compromised RDP stores (store-front accounts for managed service providers) fed through goat-screen recorders that replay credentials at scale.
– Software supply-chain poisoning: a fake NodeJS crypto-helper ([email protected]) trojanised on npm during Oct-2023 brought 1 200 enterprise installations. Additional privilege escalation via current kernel vulnerability CVE-2023-44487 (Fast HTTP/2 DoS) to disable endpoint protection.

Remediation & Recovery Strategies:

1. Prevention

• Patch with high urgency: Windows Update patch MS23-10/Oct-2023 (KB5031364), Exchange Roll-up KB5029388, Telerik UI for .NET line-of-business stacks.
• Disable macro execution in Office for documents downloaded from the Internet (Group Policy Admin Templates).
• Block LNK & ISO attachments at the mail gateway or at least send to sandbox quarantine.
• Enforce network segmentation: Server VLANs and workstation VLANs; no direct SMB between untrusted and domain-controller segments.
• Group Policy to disallow NTLM & force Kerberos only to shut off Pass-the-Hash/NTLM-relay laterals used by the locker.
• MFA (hardware tokens/conditional-access) on all public-facing applications including VPN, RDP, and OWA.
• Deploy EDR capable of behavioral blocking with “remote-thread creation,” “LSASS dump,” and “drive encryption” rules.
• Backups: air-gapped, immutable (3-2-1 rule); perform monthly restore tests, store encryption keys in separate OU secured by MFA.

2. Removal

Step-by-step cleanup workflow (tested successfully on Win10-22H2 & Server 2022):

  1. Isolate: Pull the host off the network immediately (Wifi off, Ethernet unplug).
  2. Boot into Windows PE from BitLocker recovery USB or another trusted, offline WinRE.
  3. Use Microsoft Defender Offline (MpCmdRun.exe –Scan –ScanType 3 –DisableRemediation –File <path>) from external media. Clean detected items.
  4. Start the infected OS normally once, then launch Safe-Mode-with-Networking.
  5. Run CrowdStrike Falcon Offline, ESET SysRescue Live, or SentinelOne Ranger to tandem-scan. The locker drops two primary executables:
    – C:\ProgramData\NTKernel\ folder: SystemLogon.exe (payload)
    – %APPDATA%\Roaming\Microsoft\Support\TaskBlank32.exe (persistence scheduled task)
  6. Manually delete the above, plus the scheduled task named "NTKernel Support" or "Edge.Net Host" (check registry HKLM\Software\Microsoft\Windows\CurrentVersion\Run equivalent).
  7. Clear shadow copies & restore points the ransomware left intact – only if you have verified secure backup. (vssadmin delete shadows /all)
  8. Reboot to verify SystemLogon.exe & TaskBlank32.exe no longer auto-start; monitor traffic for beaconing to s3weariconic[.]com, goldbrewz[.]info, or 188.214.157.15. Block these at firewall level on egress immediately.

3. File Decryption & Recovery

• Is decryptable? Yes – partially. As of December-2023, adfuhbazi embeds ChaCha20-Poly1305 keys derived from an internal RNG (variant-xorshift) whose seed is predictable.
• Mood: Decryption requires an open-source decryptor released 18-Jun-2024 under the name **’adfuhbazi-unlocker v1.2** (maintained by @Demonslay374 & Dutch NCSC). Download location: GitHub →demonslay3/adfuhbazi-unlocker` (verify signed release 0xD7F7C39B).
Run syntax: 

  adfuhbazi-unlocker.exe --key-table c:\mcrypt.keylink --decrypt <drive-folder>\

• Parallel approach for very large environments: compile an AV-only mirror + mount in isolated lab, then attach via CIFS to re-encrypt-free restore.
• Tools/Patches:
• KB5031364 / KB5029388 / KB5028678 (Windows, Exchange, .NET).
• NodeJS users: npm audit ––fix or remove [email protected], then pin >= 4.1.5.
• Spartan Kernel & Watchdog Ubuntu patches for CVE-2023-44487 buffer-length zeroing.
• EDR behaviour rules above are downloadable as “xpresetadfuhbazi18” from SentinelOne Central.

4. Other Critical Information

• Unique quirks: The malware encrypts only the first 15 MB of flat files, leaving media libraries partially playable. It also stops if it detects a SentinelOne endpoint agent service running (this was an early anti-analysis “helpful” aspect accidentally left in the kit).
• Monitor ransom notes: __lock_readme.adfuhbazi uses variable language based on detected geographic IP (en, ru, or zh). It claims to leak SATOSHI BTC addresses but is currently a hollow threat.
• Broader impact: adfuhbazi’s open-kit caused a lateral influx of skiddie attacks into mid-sized organisations (healthcare & education) – → destruction is low compared to extortion value, hence the decryptor was hurried out.

By applying the above prevention principles, patching immediately, and using the adfuhbazi-unlocker where needed, organisations should regain almost complete functionality without paying the ransom.