Analysis by: Jeffrey Francis Bonaobra

 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 2,550 bytes
Tipo de archivo LNK
Residente en memoria No
Fecha de recepción de las muestras iniciales 28 Apr 2022

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%\rzsPrHsBem.ps1

(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:

  • %System%\cmd.exe /v:on /c {filename}.lnk||goto&p^o^w^e^r^s^h^e^l^l.e^x^e -c "&{[System.Text.Encoding]::ASCII.GetString([System.Convert]::FromBase64String('{encoded base 64}')) > "%User Temp%\rzsPrHsBem.ps1"; powershell -executionpolicy bypass -file "%User Temp%\rzsPrHsBem.ps1"; Remove-Item -Force "%User Temp%\rzsPrHsBem.ps1"
  • powershell.exe -c "&{[System.Text.Encoding]::ASCII.GetString([System.Convert]::FromBase64String('{encoded base 64}')) > "%User Temp%\rzsPrHsBem.ps1"
  • %System%\WindowsPowerShell\v1.0\powershell.exe" -executionpolicy bypass -file %User Temp%\rzsPrHsBem.ps1

(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).)

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\rzsPrHsBem.ps1

(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).)

Download Routine

This Trojan saves the files it downloads using the following names:

  • %User Temp%\pFXxlnhRVh.pRK

(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).)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}technologies.com.pk/apitest/1r8uV/
  • http://{BLOCKED}u.vn/components/gMXyb7/
  • https://www.{BLOCKED}teldiligencias.com.mx/api/ga/
  • http://www.{BLOCKED}te.cmru.ac.th/web53photo/anKeOTOIYXxzOtlIS9D/
  • http://{BLOCKED}rup.dk/modlogan/DAbeNM/
  • http://{BLOCKED}e.me/wp-content/DTN/