Analysis by: Neljorn Nathaniel Aguas
 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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

It does not have any propagation routine.

It does not have any backdoor routine.

  TECHNICAL DETAILS

File Size: 713980912 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 13 Sep 2023
Payload: Connects to URLs/IPs, Drops files, Collects system information, Steals information, Modifies system registry

Arrival Details

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

Installation

This Trojan Spy drops the following files:

  • %ProgramData%\MuteApps\MDOH.exe ← Dropped copy of itself with different file size
  • %ProgramData%\MuteApps\uninstall.dat ← Contains the response received from the contacted URL in HTML format
  • %Application Data%\screen.jpg ← Contains the captured screen from the affected system
  • %User Temp%\tmp1B7E.tmp.bat ← Contains a batch code that executes the dropped %ProgramData%\MuteApps\MDOH.exe after 3 seconds

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • powershell runas -Command Add-MpPreference -ExclusionPath '{Malware Path}\{Malware File Name}
  • -o xmr-eu1.nanopool.org:14433 -u 46P7ufDSCru9nnoVhSdPMRGHGuxnFrwTRP2kBa6ZyinnUpMWgTVEPqgTQXUgYEPc7CNKqgVLQFSJAWCSL3HuRVStS4G7cBX --tls --coin monero --max-cpu-usage=50 --donate-level=1 -opencl
  • cmd /c schtasks /create /f /sc MINUTE /mo 5 /RL HIGHEST /tn "MDOH" /tr "%ProgramData%\MuteApps\MDOH.exe"

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • MDOH

Propagation

This Trojan Spy does not have any propagation routine.

Backdoor Routine

This Trojan Spy does not have any backdoor routine.

Rootkit Capabilities

This Trojan Spy does not have rootkit capabilities.

Information Theft

This Trojan Spy gathers the following data:

  • CPU Information
  • GPU Information
  • RAM Information
  • OS Information
  • Computer Name
  • Username
  • System Locale
  • Region
  • Installed Anti-Virus Products
  • Running Processes
  • Screen Resolution
  • Screen Capture

Stolen Information

This Trojan Spy sends the gathered information via HTTP POST to the following URL:

  • http://{BLOCKED}.{BLOCKED}.{BLOCKED}.241/BEBRIK.php

Other Details

This Trojan Spy adds the following registry keys:

HKEY_CURRENT_USER\MDOH

It connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.{BLOCKED}.241/SOSORRY.php
  • http://{BLOCKED}.{BLOCKED}.{BLOCKED}.241/EOK.php
  • http://{BLOCKED}.{BLOCKED}.{BLOCKED}.241/TOKYO.php
  • http://{BLOCKED}.{BLOCKED}.{BLOCKED}.241/CHECK.php

It does the following:

  • It creates the following scheduled task:
    • Name: MDOH
    • Trigger: Daily (After triggered, repeat every 5 minutes indefinitely)
    • Action: cmd /c %ProgramData%\MuteApps\MDOH.exe
  • It steals browser data from:
    • Opera
    • Mozilla Firefox
  • It sends the stolen information depending on the following intervals:
    • 15 seconds
    • 30 seconds
    • Random number of seconds
  • It uses XMRig to mine the following cryptocurrency coins in the affected system:
    • Monero
    • Raven
    • Verus
  • It uses binary padding to inflate its file size and its dropped %ProgramData%\MuteApps\MDOH.exe file

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 18.704.08
FIRST VSAPI PATTERN DATE: 18 Sep 2023
VSAPI OPR PATTERN File: 18.705.00
VSAPI OPR PATTERN Date: 19 Sep 2023

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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: MDOH
    • Task to be run: cmd /c %ProgramData%\MuteApps\MDOH.exe
  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 5

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_CURRENT_USER\
    • MDOH

Step 6

Search and delete these files

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %ProgramData%\MuteApps\MDOH.exe
  • %ProgramData%\MuteApps\uninstall.dat
  • %Application Data%\screen.jpg
  • %User Temp%\tmp1B7E.tmp.bat

Step 7

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %ProgramData%\MuteApps

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TrojanSpy.MSIL.REDLINE.YJDIM. 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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