Analysis by: Melvin Jhun Palbusa
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

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

File Size: 2,297,503 bytes
File Type: PS1
Memory Resident: No
Initial Samples Received Date: 18 Apr 2024
Payload: Disables AV, Modifies system registry

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 adds the following processes:

  • netsh.exe advfirewall set allprofiles state off

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USERU\Software\Classes\
CLSID\{fdb00e52-a214-4aa1-8fba-4357bb0072ec}\InProcServer32
(Default) = C:\IDontExist.dll

Process Termination

This Trojan terminates the following services if found on the affected system:

  • WdNisSvc
  • WinDefend

Other Details

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Classes\
CLSID\{fdb00e52-a214-4aa1-8fba-4357bb0072ec}

HKEY_CURRENT_USER\Software\Classes\
CLSID\{fdb00e52-a214-4aa1-8fba-4357bb0072ec}\InProcServer32

It does the following:

  • Adds the following username to Administrator group and Remote Desktop Users:
    • System32
  • It bypasses the Antimalware Scan Interface (AMSI).
  • Disable Windows Defender
  • Deletes itself after execution

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 19.316.02
FIRST VSAPI PATTERN DATE: 03 May 2024
VSAPI OPR PATTERN File: 19.317.00
VSAPI OPR PATTERN Date: 04 May 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

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_CURRENT_USERU\Software\Classes\CLSID\{fdb00e52-a214-4aa1-8fba-4357bb0072ec}\InProcServer32
    • (Default) = C:\IDontExist.dll

Step 4

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Classes\CLSID\{fdb00e52-a214-4aa1-8fba-4357bb0072ec}\InProcServer32
  • In HKEY_CURRENT_USER\Software\Classes\CLSID\{fdb00e52-a214-4aa1-8fba-4357bb0072ec}

Step 5

Scan your computer with your Trend Micro product to delete files detected as Trojan.PS1.XWORM.AC. 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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