Analysis by: Maria Emreen Viray
ALIASES:

Trojan:MSIL/AgentTesla.AMID!MTB (MICROSOFT)

 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 uses the Windows Task Scheduler to add a scheduled task that executes the copies it drops.

  TECHNICAL DETAILS

File Size: 967,168 bytes
Memory Resident: Yes
Initial Samples Received Date: 01 Jun 2022
Payload: Connects to URLs/IPs, Drops files, Collects system 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 copies of itself into the affected system and executes them:

  • %Application Data%\fseekdata\fseekdata.exe

(Note: %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).)

It drops the following files:

  • %ProgramData%\{Random characters}\{GUID}{Random characters}.zip (contains aggregated system information to be sent to C2)

(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 uses the Windows Task Scheduler to add a scheduled task that executes the copies it drops.

It adds the following processes:

  • "%Windows%\Microsoft.NET\Framework\v4.0.30319\vbc.exe"
  • "cmd.exe" /C schtasks /create /sc minute /mo 1 /tn "Nafnias" /tr "'%Application Data%\fseekdata\fseekdata.exe'" /f
  • "cmd.exe" /C copy "{Malware path and name}" "%Application Data%\fseekdata\fseekdata.exe"
  • "%System%\cmd.exe" /c taskkill /im vbc.exe /f & timeout /t 6 & del /f /q "%Windows%\Microsoft.NET\Framework\v4.0.30319\vbc.exe" & del %ProgramData%\*.dll & exit

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %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).. %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 creates the following folders:

  • %ProgramData%\{Random characters} (contains stolen information)
  • %Application Data%\fseekdata

(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).)

It injects codes into the following process(es):

  • %Windows%\Microsoft.NET\Framework\v4.0.30319\vbc.exe

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

Information Theft

Upon execution of the affected application, it gathers the following information:

  • Telegram session data
  • Cryptocurrency wallet data
  • Browser data (e.g. cookies, downloads, history, credentials, autofills, credit card data)
  • Date executed
  • Machine ID
  • GUID
  • HWID
  • Working path
  • Product name
  • Computer name
  • User name
  • Resolution
  • Operating system information
  • Keyboard layout
  • Datetime executed
  • RAM information
  • Processor information
  • Video card information
  • Running processes
  • Screenshot

Other Details

This Trojan Spy does the following:

  • It connects to the following URL to resolve its configuration:
    • https://{BLOCKED}.me/{BLOCKED}0412/
    • https://{BLOCKED}c.social/{BLOCKED}6
    As of this moment, if it receives the following URL it will use this IP to send its stolen information: http://{BLOCKED}.{BLOCKED}.11.124
  • It downloads the following archive in %ProgramData% upon resolving its configuration:
    • update.zip
    which contains the following normal files:
    • freebl3.dll
    • mozglue.dll
    • msvcp140.dll
    • nss3.dll
    • softokn3.dll
    • vcruntime140.dll
    • msvcp140.dll

It terminates itself if any of the following computer name(s) are found in the affected system:

  • JohnDoe
  • HAL9TH

It adds the following scheduled tasks:

  • Task Name: Nafnias
  • Task to run: %Application Data%\fseekdata\fseekdata.exe

(Note: %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).)

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 17.600.08
FIRST VSAPI PATTERN DATE: 01 Jun 2022
VSAPI OPR PATTERN File: 17.601.00
VSAPI OPR PATTERN Date: 02 Jun 2022

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.XXPE50FFF057

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

Restart in Safe Mode

[ Learn More ]

Step 5

Deleting Scheduled Tasks

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

  • Task Name: Nafnias
  • Task to run: %Application Data%\fseekdata\fseekdata.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 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%\update.zip
  • %ProgramData%\vcruntime140.dll
  • %ProgramData%\softokn3.dll
  • %ProgramData%\nss3.dll
  • %ProgramData%\msvcp140.dll
  • %ProgramData%\mozglue.dll
  • %ProgramData%\freebl3.dll
  • %Application Data%\fseekdata\fseekdata.exe

Step 7

Search and delete these folders

[ 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%\{Random characters}
  • %Application Data%\fseekdata

Step 8

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