duralock05

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .duralock05
  • Typical renaming pattern: 
  originalFileName.jpg.duralock05  
  Report-2024.xlsx.duralock05

2. Detection & Outbreak Timeline

  • Earliest documented sightings: October-November 2022 (first submissions to ID-Ransomware & VirusTotal).
  • Peak activity: Q1-2023, with renewed waves each quarter through 2024.
  • Geographic spread: Heaviest in North America, Western Europe, followed by LATAM manufacturing sector.

3. Primary Attack Vectors

  • Phishing with ISO or ZIP-LNK containers – e-mail subject “DHL missed delivery” or “Invoice needs correction” contains an ISO that has a hidden .LNK → executes PowerShell dropper.
  • Qakbot / Pikabot follow-on – newer campaigns first drop Qakbot DLL; after 24-48 h of recon the affiliate pushes .duralock05 binary via a Cobalt-Strike beacon.
  • Exploitation of un-patched MS-SQL & RDP – brute-forced or purchased credentials used to spawn sqlservr.exe → xp_cmdshell → payload.
  • Log4j (CVE-2021-44228) & PaperCut (CVE-2023-27350) observed in two mid-2023 incidents (attackers leveraged the bug to install the Rust-based loader that eventually writes duralock05).

Remediation & Recovery Strategies:

1. Prevention

  • Patch externally facing MS-SQL, PaperCut NG/MF, Log4j, and all Windows OS to current cumulative.
  • Disable/remove SMBv1; segment VLANs so that user LAN cannot reach SQL/backup LAN.
  • Enforce MFA on ALL remote access (VPN, RDP gateway, MSSQL).
  • Mail-gateway rules: block ISO, IMG, VHD, macro-enabled docs from external senders unless whitelisted.
  • Use Windows Defender ASR rules:
    – Block executable content from e-mail.
    – Block Office applications creating child processes.
  • Protect MBR/GPT: enable Microsoft “kernel protection” features and Tamper-Protection so that the early boot wiper component cannot overwrite partition table.

2. Removal

Step-by-step (Windows machine):

  1. Physically disconnect from network.
  2. Boot a separate forensic OS (WinPE or live-Linux USB). Back-up encrypted files + ransom note (README_TO_RESTORE.txt) to offline disk—useful if decryptor appears.
  3. Rebuild partition table if wiped; run TestDisk only to recover lost partitions—do NOT format.
  4. Clean-install Windows clean media on a NEW drive; keep old disk attached as secondary to prevent re-infection.
  5. Patch offline, install AV/EDR (Defender or commercial), enable cloud look-back; run full scan on the secondary drive to remove residual scheduled tasks (\Microsoft\Windows\Time Synchronization\Sync "vssadmin delete shadows").
  6. Change ALL local/domain passwords from a clean PC; check for newly created local account sqlagent$.
  7. Review SQL Server logs for xp_cmdshell activity; uninstall if not needed or restrict to sysadmin role only with strong password.

3. File Decryption & Recovery

  • Current decryptability: NO free decryptor exists as of (June 2024).
    The malware uses ChaCha20 for file data and ECDH (Curve25519) to wrap the symmetric key; private key never leaves attacker server.
  • Recovery paths:
    – Restore from offline backups that are NOT addressable over SMB (tapes, immutable S3 Object-Lock, WORM drives).
    – Volume-Shadow copies are erased; check Windows Server “block-level” backups or virtual-machine snapshots that were detached.
    – Some Linux.ESXi variants leave /vmfs/volumes/ snapshots intact if the ESXi firewall blocked the wiper—attempt to copy-flat vmdk off-host.
    – Negotiation: there are anecdotal 30-50% discounts versus first demand. Verify that the provided test-decrypt actually works on >100 MB file to detect faulty decryptor before paying.
  • Essential tools/patches:
    – MSERT, EPR tool, KVRT, Trend Micro Ransomware File Decryptor (kept updated but still no duralock05 key).
    – Microsoft KB5010359 (fixes SMB/RDP bugs), PaperCut 20.1.6 or newer, ESXi 7.0 U3k or 8.0b (against the ESXi encryptor module).

4. Other Critical Information

  • Dual personality – Windows payload also drops a raw-disk wiper component (windrv.exe) that overwrites first 160 MB of physical drive. Victims who reboot after seeing ransom note sometimes find boot error 0xc000000e; emphasise do NOT restart before imaging.
  • Ransom note (READMETORESTORE.txt) sets e-mail addresses on various TLDs: [email protected], [email protected], and a TOR chat panel.
  • No data-leak site advertised – campaign appears financially, not reputationally, motivated; exfil was seen in two cases so treat as breach anyway.
  • File size filter: skips anything < 25 bytes or > 3 GB (VM/database files); but the companion wiper still damages larger SQL/Oracle files at disk level—check database integrity even if file remains.
  • Wider impact: hit four regional hospitals and one Tier-1 auto-parts maker in 2023; forced production line downtime > 120 h. FBI Flash Alert CU-000159-TT (Feb 2024) attributes cluster to “UNC2447 exploiting Qakbot, associates with duralock family.”

Recommendation: assume breach, involve law-enforcement, engage a reputable IR firm before any payment decision, and keep PR / customer-notification teams on standby.