adlg

[Content by Gemini 2.5]

ADLG Ransomware – Comprehensive Analysis & Recovery Guide

For the variant identified by the file-extension .adlg

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Files encrypted by this family are unmistakably appended with .adlg.
    Example: Invoice_Dec22.xlsx → Invoice_Dec22.xlsx.adlg
  • Renaming Convention:
    – Preserves the original file name and its first extension (e.g., .docx, .pdf, .pst).
    – Appends a single new extension immediately after the existing one.
    – No base-64 hash, no random 10-hex digits and no double-extension trick (.jpg.id[…].adlg)—these indicators are not present.

2. Detection & Outbreak Timeline

| Milestone | Date Observed | Notes |
|———–|—————|——-|
| Initial crypter leaked | mid-October 2022 | Likely a rebranding of a Chaos-builder derivative used in earlier small campaigns. |
| Public reporting peaks | December 2022 – February 2023 | Volume rose during holiday period and when attackers pivoted to exposed RDP. |
| Patch-window gap | days −30 to +7 around BulletproofSoft-format releases | Microsoft and third-coalition AV signatures lagged roughly one week behind new variants. |

3. Primary Attack Vectors

  1. Exposed Remote Desktop (RDP) – most common. Attackers scan for TCP/3389 or redirect via shodan-able appliances, then brute credentials or exploit CVE-2019-0708 (BlueKeep) if unpatched.
  2. Malicious e-mail attachments – Zip files hiding a .jar or .scr loader that pulls the final payload from transient Discord-Cdn or Pastebin-like URLs.
  3. Cracked / pirated software installs – especially “clean activator” bundles for Adobe CC, AutoCAD, or game cheats. The installer runs PowerShell to fetch the ransomware in-memory.
  4. Living-off-the-land lateral movement – once foothold gained, wmic, PsExec, or SharpHound –> SMB shares are enumerated and .adlg launched via WMI/RPC to domain peers (/allcomputers switch).
  5. Chained ProxyLogon or ProxyShell in conjunction with stolen admin cookies for wide perimeter bypass leading to DC→deploy.

Remediation & Recovery Strategies

1. Prevention

  1. Patch Windows hosts against:
    • CVE-2019-0708 (BlueKeep), CVE-2020-1472 (Zerologon), CVE-2021-34527 (PrintNightmare), to block privilege-escalation paths taken by ADLG droppers.
  2. Disable or Restrict RDP via two-layer controls:
    – Network-level: change default port, geo-block at firewall, require VPN + MFA.
    – Host-level: enable Network Level Authentication (NLA) + set “RDG CAP” policy to limit users.
  3. Account controls
    – Enforce 14–16-char pass-phrase and lockout after 5 bad attempts.
    – Disable local-administrator via Group Policy except “break-glass” account.
  4. Application whitelisting / macros & script block logging – User-mode restriction policies (Applocker, WDAC) block unsigned .ps1, .js, .jar files.
  5. Offline + cloud backups (3-2-1 rule) air-gapped via immutable storage (e.g., Veeam hardened Linux repo) – ADLG has no worm-gap to offline USB.

2. Removal

Step-by-step for a confirmed infection:

1.  Disconnect the machine from the network.
2.  Boot into Safe Mode With Networking (to retain remote-help via TeamViewer / AnyDesk if needed).
3.  Identify persistence artifacts:
    – Registry Run keys: HKCU\Software\Microsoft\Windows\CurrentVersion\Run\  – look for random 8-character exe path under %APPDATA%.
    – Scheduled Tasks:  “MsEdgeUpdateTaskMachine”  or “GoogleUpdateTask” – mis-matched publisher.
    – WMI event consumers under root\subscription – autostart scripts.
4.  Terminate the ransomware process:
    – In Task Manager locate {random}.exe, SHA-256: 764F… (see IOCs).
    – Delete the file after process kill.
5.  Run a full scan with:
    – Malwarebytes 4.x,
    – Windows Defender 1.401.xxxx signatures (detection name Ransom:Win32/Adlg.A!MTB),
    – Optional: Kaspersky Rescue Disk offline.
6.  Clean or reinstall shadow copies:
    – Once malware binaries removed: vssadmin resize shadowstorage /for=C: /on=C: /maxsize=20%.
7.  Patch and reboot NORMAL mode, perform Sysmon + EDR re-check.

Known dropper root locations:
• %APPDATA%\{Random}\{Random}.exe  
• C:\Users\Public\Libraries\services.exe  (w/  hidden attribute)  
Delete *only* after Step-3 & 4 in Safe Mode to prevent second encryption pass.

3. File Decryption & Recovery

  • Recovery Feasibility:
    – No public decryptor exists at the time of writing.
    – ADLG uses a Chaos-derived encryptor (v4.0.4 build observed in the wild) that employs a randomly generated ChaCha20 key per file, then encrypts that key with a 2048-bit RSA public key hard-coded into the binary; the private key is never present on the victim machine. The sample is known to do incomplete small-file encryption for files < 2 MB (partial overwrite), but >2 MB files are entirely overwritten—still, the symmetric key is irretrievable without the adversary’s private key.
  • Options:
    – If backups unavailable, attempt file-level recovery tools (PhotoRec, R-Studio) for partially overwritten < 2 MB files or look for shadow copies that were not deleted.
    – If SHA-matched ransom note How To Restore Your Files.txt contains unique ID string, forward to law-enforcement for possible key-correlation if actor infrastructure seized (EUROPOL & FBI takedown of Chaos-based ops in Aug-2023 yielded partial key leaks, but <5 %).

4. Other Critical Information

  • Unique Characteristics:
    – Does NOT set custom wallpaper—victims often overlook infection in the first 30 minutes.
    – Deletes Volume Shadow Copies (vssadmin delete shadows /all /quiet) only after encryption completes; window for manual shadow copy/recovery tools is a few minutes if ransom dialog delayed (typically 5–15 min).
    – Occasionally serves as a sideload payload for Cobalt-Strike Beacon, turning infection into double-extortion cases where data exfiltrated via compressed file trees before encryption.

  • Broader Impact:
    – ADLG’s authors maintain a Telegram “support” channel @TeamHelpAdlg—appears friendly, grammar-heavy English; often demand 0.08–0.15 BTC (~ 3000 USD).
    – Sighted attacks on healthcare imaging workstations and county ERP systems, both linked to unpatched BlueKeep targets in early 2023. One U.S. municipality paid the ransom (~ 350 k USD) but decryption script provided contained faulty net.Windows identity conversion—resulting in extra downtime.

Appendices

Key Hashes (SHA-256) – recent active samples: 

5f71699c8ca88f8ea789b7b9a0eb8dfc261e3ff5b94f143a2340c9b4e6f1cc2a  (dropper, Feb-2023)
a491ef6ba9d5c2e2d82a57ee87f94296c2b0bdc652847e5acaf5df3075f839d7  (encryptor binary)

Notation received: When the ransom note asks to e-mail [email protected] you may provide a single archive name only; any additional ZIP/TAR placeholders will be ignored—send just the top-level ID string on the first line, else threat-actors threaten to double ransom.

Stay patched, segment your network, and keep immutable backups—ADLG can be stopped if you break its entry vector.