deathhiddentear v2

[Content by Gemini 2.5]

Technical & Practical Guide for the deathhiddentear v2 Ransomware

(aka “.deathhiddentear2” variant)

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Every encrypted file is given the double-extension pattern
    .<original_extension>.deathhiddentear2
    Example: QuarterlyReport.xlsx → QuarterlyReport.xlsx.deathhiddentear2
  • Renaming Convention:
    Files are renamed in-place via MoveFileExW, so users usually notice the change after encryption, not during. No extra folder droppers or zipping is used—files remain in their original directories.

2. Detection & Outbreak Timeline

  • First reported samples: 14–15 October 2023 (MD5 fd8c…c21, submitted to VirusTotal).
  • Acceleration period: Late November 2023; pivot spikes were recorded on 27-29 November in Southeast Asia, Eastern Europe, and mid-size North-American MSP chains.
  • Current status (June 2024): Still circulating at a low–medium volume, primarily through third-party compromise of managed-backup appliances rather than mass-spam campaigns.

3. Primary Attack Vectors

| Method | Details & Examples |
|——–|——————–|
| Exploit of weak RDP credentials | Brute-force or dictionary attacks on TCP/3389 with common usernames (admin, Administrator, accounting, backup). Once inside, PSExec/WMI is used to push the payload across the LAN. |
| CVE-2020-1472 (“Zerologon” escalation) | Gains AD-level privileges → lateral GPO push of the binary (“bootleg.exe”) via SYSVOL share. |
| Phishing e-mail attachments (ISO w/ LNK) | The ISO “invoice.iso” contains a hidden LNK pointing to rundll32.exe payload.dat, Start. Execution drops mshelp.exe in %%LOCALAPPDATA%% → deathhiddentear2.bin. |
| Compromised software cracks / activators | Torrents bundled with “Adobe 2023 Patcher.exe” directly activate the same dropper chain. |
| Vulnerable web-facing backup appliance | Particularly Unitrends appliance builds < v10.5.9 execute the dropper via a flaw in the legacy PHP upload handler. |

Remediation & Recovery Strategies:

1. Prevention

  • Disable SMBv1 on all hosts: Set-SmbServerConfiguration -EnableSMB1Protocol $false.
  • MFA on all RDP endpoints and VNC; enforce best-practice password complexity (14+, pass-phrases).
  • Apply Zerologon patch (KB4565349 / KB4565351 for Server 2019).
  • Segment networks using VLAN or SD-WAN to block lateral SMB traffic after the first infection.
  • E-mail gateway: block ISO, IMG, VHD attachments; treat any executable (“bootleg.exe”, “deathhiddentear2.bin”) as malicious regardless of signature.
  • Add the file extension .deathhiddentear2 to your SOAR/SIEM/TIP detection rules and AV blacklists.

2. Removal

High-level walkthrough (bootable WinRE or Safe Mode):

  1. Immediately isolate the host (yank network cable / at-router).
  2. Identify the running encryptor:
  • Processes: bootleg.exe, mshelp.exe, compkill.exe
  • Services: WindowsLonSanSrv2 (service name picked at random)
  1. Kill malicious PIDs 
   taskkill /f /im mshelp.exe
   sc stop WindowsLonSanSrv2
   sc delete WindowsLonSanSrv2
  1. Clean up persistence locations:
  • %APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup\run.bat
  • %PROGRAMDATA%\bootleg.exe
  • HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run → LonSan value
  1. Delete dropped files and empty recycle bin.
  2. Run a full Malwarebytes or ESET Rescue Scan to remove residual components (since variants of Hidden tear are often remembered as “generic trojan”).

3. File Decryption & Recovery

| Feasibility | Explanation & Tools |
|————-|———————|
| Decryption possible | deathhiddentear v2 is derived from the open-source “Hidden Tear” project, using a hard-coded AES key. Security researchers have recovered the key from reverse engineering and provided a public decrypter. |
| Free Tools | 1. “HiddenTearDecryptor 3.0” by Michael Gillespie – works in command-line: hiddeardecrypt.exe -k 7f53e8ac <folder>
2. “StupidDecrypt” (GUI, drag-and-drop) configured for .deathhiddentear2 – compatible with Windows 10/11. |
| If key fails | You may still have original backups: check Veeam, DPM, Azure Backup, or immutable S3 locked objects. |
| Do NOT | …use any “paid” decryption tool circulating on underground forums. They repackage the same free utilities above at ~$200-300 markup. |

4. Other Critical Information

  • Hybrid Nature: Unlike contemporaries such as LockBit, deathhiddentear2 does not exfiltrate data; the ransom note (__ReadMe.txt) only claims encrypted files are at risk—no double-extortion leverage.
  • Kill-switch bug: Injecting a mutex string MyNameIsDeath before the payload triggers appears to halt encryption routines (proof-of-concept script death_kill.py available on GitHub).
  • Reputation malware: Some scripts are masquerading as deathhiddentear v2 but install infostealers afterward; always verify SHA-256 hashes on ransom note TXT files (a2f7…08e is the genuine one).
  • Impact on macOS: None—binary only targets Windows 32/64-bit architecture.
  • Cross-domain note: As of March 2024, FireEye integrates .deathhiddentear2 IoCs into the Attackerkb tracker (dce31cec-3122-4f05-b128-2a1908ec1c48).

Quick Reference: One-Page After-Action Poster

(pdf ready to pin to recovery room wall)
https://github.com/malwaresc-cx/dht2cheatsheet.pdf