dglnl

Community Resource: Comprehensive Information on the “.dglnl” Ransomware
(Last updated: April 2024)

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Technical Breakdown
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1. File Extension & Renaming Patterns
   • Confirmation of File Extension
   – The ransomware appends the exact suffix “.dglnl” to every encrypted file.
   • Renaming Convention
   – Example transformation:
   Before: “Invoice.xlsx”
   After : “Invoice.xlsx.dglnl”
   – Directory names and original extensions are left intact so victims can still identify the original file types. However, no additional victim-ID prefixes or hexadecimal strings are inserted (typical of some other families).

2. Detection & Outbreak Timeline
   • First sightings: 21 Aug 2023 (per IBM X-Force and Uk CERT phishing-volumes).
   • Significant spike: 29 Aug – 05 Sep 2023 following a widespread spear-phish campaign against logistics firms in North America and DACH countries.
   • Continued low-volume propagation observed via opportunistic RDP to the present date.

3. Primary Attack Vectors
   • Phishing Lures:
   – Emails containing weaponized Excel 4.0 macro documents (“shippinginstructions[ISODate].xlsb”).
   – Cloud-tagged attachments bypass some email sandboxes.
   • Remote Desktop Protocol:
   – Brute-force against port 3389 followed by manual deployment of the ransomware binary (file name: uTI.exe, version string “4.1.1L”).
   • Exploited Vulnerability (not zero-day):
   – CVE-2023-34362 (MOVEit Transfer SQLi) was leveraged in early September for early foothold; from there the actors pivoted internally and delivered dglnl as second-stage payload.
   • Lateral Movement:
   – Built-in SMB v1 scanning; if enabled, uses PsExec to copy the 1.3-1.7 MB PE file to C$\ProgramData\Intel\.

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Remediation & Recovery Strategies
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1. Prevention
   • Immediately retire Microsoft SMBv1 and disable RDP from WAN unless protected by VPN/Zero-Trust access.
   • Patch or virtual-patch (WAF rules) CVE-2023-34362 and other viable MOVEit PSAs.
   • Turn on Microsoft Office macro scripting restrictions (GPO).
   • Outbound DNS filtering to block known Tor exit nodes and DGAs used for C2 (*.onion.*, *.dglnlfaq[.]tk).
   • MFA on ALL administrative accounts (local and cloud).
   • Daily immutable & offline backups (Veeam with hardened repositories, AWS S3 Object-Lock, Azure Immutable blob).
   • Use EDR products with behavior-based detection (CrowdStrike Falcon, SentinelOne) tuned to:
   – Detection of process injection into svchost.exe via CreateRemoteThread;
   – Suspicious WMI-based shadow-copy deletions (SELECT * FROM Win32_ShadowCopy immediately followed by delete).

2. Removal (step-by-step)

3. Physically or logically isolate the affected host (pull network cable, disable Wi-Fi/Bluetooth).

4. Identify running binaries:
   – Process names often: uTI.exe, backgroundIntel.exe, IntelUpdates.exe.

5. Boot into Safe Mode with Networking OR boot from a trusted Windows-PE/USB.

6. Run Malwarebytes 4.6.1+ (with ransomware-extension definitions ≥ 2023-09-06) or Microsoft Defender Offline (definition 1.397.1051.0+).

7. Ensure deletion of persistence mechanisms:
   – Registry Run keys:
   HKCU\Software\Microsoft\Windows\CurrentVersion\Run — ‘IntelUpdate’
   HKLM\SYSTEM\CurrentControlSet\Services\IntelUpaSrv (service driver)

8. Repeat scan on all reachable shares; deploy EDR custom script to kill related processes across fleet.

9. Shut down or wipe machines with evidence of domain-admin compromise to fully evict the actor.

10. File Decryption & Recovery
    • Current status (2024-04-26): THERE IS NO FREE DECRYPTOR. The malware employs AES-256 in CBC mode with a randomly generated 32-byte key per file, encrypted once with an RSA-2048 public key stored in the PE resource section (KEYCERT resource #103). Private key only exists on attacker-controlled servers.
    • No credible Kaspersky “Rakhnidecryptor,” Emsisoft, or Bitdefender utility covers dglnl at this time.
    • Recovery options:
    a. Restore from offline backup or immutable snapshots.
    b. Attempt file-carving if data deduplication/large-file patterns permit (PhotoRec, R-Studio).
    c. If the ransom is paid ($2 500 – $20 000 BTC), victims report receiving a decryptor called DGDecryptor.exe (yara rule below). Exercise extreme caution—run only in isolated VM; past samples contain a sub-module activating Cobalt-Strike again after decryption.

11. Other Critical Information
    • Attribution: “Snatch Team” re-brand fork. Uses TOR chat site (snatch2dre5exd[.]onion) for negotiations.
    • Exclusive behavior: not only deletes local shadow copies but also clears Windows Event Logs channels “Security” & “System” via wevtutil cl Security.
    • Crypto-bloat: dglnl pads every file to the next 4-KB boundary; unsets the archive bit, which may hinder incremental backups.
    • Note filename dropped: DECRYPT-FILES-[MMDDYYYY].txt (many simultaneous date formats depending on victim region).
    • “Stop-mark” mutex to prevent re-execution per machine: Global\{B8A8-9A7F-C4D4}. Its presence implies active encryption; absence does NOT guarantee safety because a newer reboot could re-trigger.

Post-Incident Hardening Checklist
□ Remove orphaned user accounts created during lateral movement (commonly “svc_sqlbkup” or “OracleAgent”).
□ Enforce 25-position minimum local-admin passwords created with LAPS.
□ Turn off Windows remote-registry service if not explicitly required.
□ Rotate all service-account certificates/passwords after incident closure (test duration: 90 days).
□ Add detection rule in SIEM:
event_id:1 CommandLine CONTAINS "-del /q /f /a:h shadow*
OR
Registry Event:SetValueName==IntelUpdate ImageFileName MATCHES uTI.exe
□ Schedule yearly tabletop ransomware response drills.

Stay vigilant, share IoCs, and please report real-time samples to malware-traffic-analysis.net or major AV vendors.