Analysis by: Bren Matthew Ebriega

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan 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

Tamaño del archivo 10,240 bytes
Tipo de archivo EXE
Residente en memoria No
Fecha de recepción de las muestras iniciales 28 Sep 2021

Arrival Details

This Trojan 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 drops the following files:

  • %User Temp%\{4 Hex Characters}.tmp\b2e.exe
  • %User Temp%\{4 Hex Characters}.tmp\batchfile.bat
  • %User Temp%\selfdel0.bat → Deletes dropped files and folder.

(Note: %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:

  • %User Temp%\{4 Hex Characters}.tmp\b2e.exe %User Temp%\{4 Hex Characters}.tmp\b2e.exe {Current FilePath} {Current FilePath}\{Current Filename}
  • cmd /c %User Temp%\{4 Hex Characters}.tmp\batchfile.bat
  • cmd /c %User Temp%\selfdel0.bat

(Note: %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 creates the following folders:

  • %User Temp%\{4 Hex Characters}.tmp

(Note: %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).)

  SOLUTION

Motor de exploración mínimo 9.800
Primer archivo de patrones de VSAPI 16.996.03
Primera fecha de publicación de patrones de VSAPI 29 Sep 2021
Versión de patrones OPR de VSAPI 16.997.00
Fecha de publicación de patrones OPR de VSAPI 30 Sep 2021

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

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.DROPPER.EOL. 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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