TrojanSpy.MSIL.NEGASTEAL.RJANLJ

 Analysis by: Neljorn Nathaniel Aguas

 ALIASES:

Trojan:MSIL/AgentTesla.MBXI!MTB [non_writable_container] (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

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.

  TECHNICAL DETAILS

File Size:

491,038 bytes

File Type:

RAR

Initial Samples Received Date:

30 Jul 2024

Payload:

Connects to URLs/IPs, Drops files

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:

  • %AppDataLocal%\MICROSOFT\Windows\PowerShell\StartupProfileData-NonInteractive
  • %User Temp%\iusmu2uw.gw3.ps1
  • %User Temp%\kcy3a44w.kcm.psm1
  • %User Temp%\au5n0kgd.02f.ps1
  • %User Temp%\kdlsfc4s.ad2.psm1
  • %User Temp%\ncmlgizh.d4s.ps1
  • %User Temp%\qa2xkce0.luu.psm1
  • %User Temp%\Log.tmp → used to log keystrokes

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local 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 drops the following copies of itself into the affected system:

  • %Application Data%\XClient.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 adds the following processes:

  • {Malware Path}\{Malware Filename}
  • "%System%\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionPath '{Malware Path}\{Malware Filename}'
  • "%System%\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionProcess '{Malware Filename}'
  • "%System%\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionPath '%Application Data%\XClient.exe'
  • "%System%\WindowsPowerShell\v1.0\powershell.exe" -ExecutionPolicy Bypass Add-MpPreference -ExclusionProcess 'XClient.exe'

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 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).)

Autostart Technique

This Trojan Spy drops the following shortcut pointing to its copy in the User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\XClient.lnk

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)

Other Details

This Trojan Spy connects to the following possibly malicious URL:

  • {BLOCKED}.{BLOCKED}.{BLOCKED}.178:7061

It does the following:

  • It hooks into an API to log keystrokes and system activity.
  • This is a RAR file containing a malicious executable upon extraction.

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

19.514.03

FIRST VSAPI PATTERN DATE:

07 Aug 2024

VSAPI OPR PATTERN File:

19.515.00

VSAPI OPR PATTERN Date:

08 Aug 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

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

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.  
  • %Application Data%\XClient.exe
  • %User Startup%\XClient.lnk
  • %User Temp%\Log.tmp
  • %AppDataLocal%\MICROSOFT\Windows\PowerShell\StartupProfileData-NonInteractive
  • %User Temp%\iusmu2uw.gw3.ps1
  • %User Temp%\kcy3a44w.kcm.psm1
  • %User Temp%\au5n0kgd.02f.ps1
  • %User Temp%\kdlsfc4s.ad2.psm1
  • %User Temp%\ncmlgizh.d4s.ps1
  • %User Temp%\qa2xkce0.luu.psm1

Step 5

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