Analysis by: Melvin Jhun Palbusa

ALIASES:

Trojan:MSIL/DynamicStealer.CT!MTB(MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 13,824 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 29 May 2023
Payload: Collects system information, Connects to URLs/IPs

Installation

This Trojan Spy adds the following folders:

  • %ProgramData%\OBIHAS

(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 drops a copy of itself in the following folders using different file names:

  • %ProgramData%\OBIHAS\nfsdfh.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 processes:

  • powershell.exe "-Command Add-MpPreference -ExclusionPath $env:UserProfile,$env:Temp,$env:ProgramData,$env:HomeDrive,$env:SystemDrive"
  • schtasks.exe /create /f /sc ONLOGON /RL HIGHEST /tn nfsdfh /tr %ProgramData%\OBIHAS\nfsdfh.exe
  • %ProgramData%\OBIHAS\nfsdfh.exe /C /choice /C Y /N /D Y /T 3 & Del\ "{Malware Filename}"

(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.)

Download Routine

This Trojan Spy connects to the following URL(s) to download its component file(s):

  • https://{BLOCKED}hubusercontent.com/L1ghtM4n/DynamicStealer/main/DLL/PasswordStealer.dll

As of this writing, the said sites are inaccessible.

Information Theft

This Trojan Spy gathers the following data:

  • BIOS Version
  • BIOS Manufacturer
  • BIOS Name
  • BIOS Release Date
  • CPU Name
  • GPU Name
  • Installed RAM
  • Motherboard Manufacturer
  • Motherboard Product
  • Motherboard Serial Number
  • Motherboard Version
  • Physical Memory(Bank Label, Capacity, Data Width, Manufacturer, Memory Type, Speed)
  • Drive Type
  • Available Space on C drive
  • OS Version
  • OS Bit Version

Stolen Information

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

  • https://{BLOCKED}egram.org/bot{@BotFather}/sendMessage?chat_id={@chatid_echo_bot}

Other Details

This Trojan Spy adds the following scheduled tasks:

  • Task Name: nfsdfh
  • Trigger: At log on
  • Action: Start a Program → %ProgramData%\OBIHAS\nfsdfh.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.)

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 18.474.03
FIRST VSAPI PATTERN DATE: 29 May 2023
VSAPI OPR PATTERN File: 18.475.00
VSAPI OPR PATTERN Date: 30 May 2023

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • TROJ.Win32.TRX.XXPE50FFF077

Step 2

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 3

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 4

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%\OBIHAS

Step 5

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%\OBIHAS\nfsdfh.exe

Step 6

Deleting Scheduled Tasks

The following {Task Name} - {Task to be run} listed should be used in the steps identified below:

  • {Task Name}: nfsdfh
  • {Task to be run}: Start a program → %ProgramData%\OBIHAS\nfsdfh.exe

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
    System Tools>Scheduled Tasks.
  2. Locate each {Task Name} values listed above in the Name column.
  3. Right-click on the said file(s) with the aforementioned value.
  4. Click on Properties. In the Run field, check for the listed {Task to be run}.
  5. If the strings match the list above, delete the task.

For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:

  1. Open the Windows Task Scheduler. To do this:
    • On Windows Vista, Windows 7, and Windows Server 2008, click Start, type taskschd.msc in the Search input field, then press Enter.
    • On Windows 8, Windows 8.1, and Windows Server 2012, right-click on the lower left corner of the screen, click Run, type taskschd.msc, then press Enter.
  2. In the left panel, click Task Scheduler Library.
  3. In the upper-middle panel, locate each {Task Name} values listed above in the Name column.
  4. In the lower-middle panel, click the Actions tab. In the Details column, check for the {Task to be run} string.
  5. If the said string is found, delete the task.

Step 7

Scan your computer with your Trend Micro product to delete files detected as TrojanSpy.MSIL.DYNAMICSTEAL.THEBIBC. 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 the following Trend Micro Support pages for more information:


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