Backdoor.Win64.VOLDEMORT.THIODBD

October 24, 2024
 Analysis by: Neljorn Nathaniel Aguas
 ALIASES:

Trojan:Win64/Voldemort.DA!MTB (MICROSOFT)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes commands from a remote malicious user, effectively compromising the affected system. However, as of this writing, the said sites are inaccessible.

It gathers certain information on the affected computer.

  TECHNICAL DETAILS

File Size:

258,048 bytes

File Type:

DLL

Memory Resident:

Yes

Initial Samples Received Date:

04 Sep 2024

Payload:

Connects to URLs/IPs, Steals information

Arrival Details

This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Backdoor Routine

This Backdoor executes the following commands from a remote malicious user:

  • Ping
  • Dir
  • Download
  • Upload
  • Exec
  • Copy
  • Move
  • Sleep
  • Exit

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • https://{BLOCKED}oogleapis.com/v4/spreadsheets/16JvcER-0TVQDimWV56syk91IMCYXOvZbW4GTnb947eE/

However, as of this writing, the said sites are inaccessible.

Information Theft

This Backdoor gathers the following information on the affected computer:

  • Generated UUID
  • Local IP
  • Hostname
  • Username
  • Program Files contents
  • Program Files (x86) contents
  • Environment Variables
  • Filename of executable
  • Infection Timestamp

Other Details

This Backdoor does the following:

  • It requires its filename to be the following to proceed with its intended routine:
    • CiscoSparkLauncher.dll
  • It waits for 5 minutes before proceeding with its routine.
  • It uses a hardcoded client ID, client secret, and refresh token to authenticate to a Google Sheets API and access a malicious Google spreadsheet.
  • It sends and stores the gathered information to the following malicious Google spreadsheet URL via HTTP PUT method:
    • https://{BLOCKED}oogleapis.com/v4/spreadsheets/16JvcER-0TVQDimWV56syk91IMCYXOvZbW4GTnb947eE/values/test!{Cell Range}?valueInputOption=USER_ENTERED

It adds the following scheduled tasks:

  • Location: {Root Directory}
    Task name: CiscoCollabHostStart
    Trigger: One time at 8:00 PM on 03/10/2023 → After triggered, repeat every 5 minutes indefinitely.
    Action: Start a program → {Loader Path}\{Loader Filename}

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

19.570.03

FIRST VSAPI PATTERN DATE:

04 Sep 2024

VSAPI OPR PATTERN File:

19.571.00

VSAPI OPR PATTERN Date:

05 Sep 2024

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Deleting Scheduled Tasks while in Safe Mode

  1. Still in safe mode, the following {Task Name}-{Task to be run} listed should be used in the steps identified below:  
    • {Task Name}: CiscoCollabHostStart
    • {Task to be run}: {Loader Path}\{Loader Filename}
  2. For Windows 7 and Server 2008 (R2) users, click Start>Computer.
    • For Windows 8, 8.1, 10, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
  3. In the Search Computer/This PC input box, type:
    • %System%\Tasks\{Task Name}
  4. Once located, select the file then press SHIFT+DELETE to delete it.
  5. Open Registry Editor. To do this:
    • For Windows 7 and Server 2008 (R2) users, click the Start button, type regedit in the Search input field, and press Enter.
    • For Windows 8, 8.1, 10, and Server 2012 (R2) users, right-click on the lower left corner of the screen, click Run, type regedit in the text box
  6. In the left panel of the Registry Editor window, double-click the following:
    • HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tree>{Task Name}
  7. Locate the created entry and take note of the registry value's data:
    • ID={Task Data}
  8. After taking note of the data, delete the registry key:
    • HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tree>{Task Name}
  9. In the left panel of the Registry Editor window, double-click the following:
    • HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tasks
  10. Still in the left panel, locate and delete the registry key with the same name as the located Task Data in step #6:
    • ={Task Data}
  11. Close Registry Editor.

Step 4

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win64.VOLDEMORT.THIODBD. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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