Analysis by: Raighen Sanchez

ALIASES:

Trojan:Win32/BatTamper.A (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • 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.

It does not have any propagation routine.

It does not have any backdoor routine.

  TECHNICAL DETAILS

File Size: 2,022 bytes
File Type: PS1
Memory Resident: No
Initial Samples Received Date: 27 Sep 2024
Payload: Drops files

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%\{random alphanumeric}.{random alphanumeric}.ps1 → deleted afterwards
  • %User Temp%\{random alphanumeric}.{random alphanumeric}.psm1 → deleted afterwards
  • %ProgramData%\loader.exe → only if the network share is accessible

(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).. %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 adds the following processes:

  • Set-MPPreference -DisableTamperProtection $true
  • Set-MPPreference -DisableBehaviorMonitoring $true
  • Set-MpPreference -MAPSReporting Disabled
  • Set-MpPreference -DisableIOAVProtection $true
  • Set-MpPreference -EnableNetworkProtection Disabled
  • Set-MpPreference -MAPSReporting 0
  • Set-MpPreference -MAPSReporting Disabled
  • Set-MpPreference -SubmitSamplesConsent NeverSend
  • Add-MpPreference -ExclusionProcess {C:\ProgramData\}
  • MpCmdRun.exe -RemoveDefinitions -All → removes Windows Defender definitions

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Rootkit Capabilities

This Trojan does not have rootkit capabilities.

Other Details

This Trojan does the following:

  • It checks if the computer name of the host matches the following:
    • K-DYNABOOK01
    • K-DYNABOOK13
    • K-DYNBK017
    • K-DYNBK034
    • K-DYNBK044
    • K-DYNBK058
    • K-HPDISK003
    • K-HPDISK004
    • K-HPDISK007
    • K-HPDISK008
    • K-HPDISK009
    • K-HPDISK010
    • K-HPDISK012
    • K-HPDISK015
    • K-HPPDK001
    • K-HPPDK002
    • K-HPPDK003
    • K-HPPRODSK01
    • K-HPPRODSK03
    • K-LATITUDE14
    • K-LATITUDE19
    • K-NAS01
    • K-OPTIPLEX011
    • K-OPTIPLEX012
    • K-OPTIPLEX013
    • K-OPTIPLEX03
    • K-OPTIPLEX090
    • K-OPTIPLEX10
    • K-OPTIPLEX11
    • K-OPTIPLEX13
    • K-OPTIPLEX19
    • K-OPTIPLEX24
    • K-OPTIPLEX26
    • K-OPTIPLEX27
    • K-OPTIPLEX31
    • K-OPTIPLEX49
    • K-OPTIPLEX90B
    • K-OPTIPLEX91
    • K-OPTIPLEX91B
    • K-PANACFSX01
    • k-server01
    • k-server03
    • K-SERVER04
    • K-SERVER05
    • K-SERVER06
    • K-SERVER17
    • SM-SERVER07
    • Z-oracle01
    • Z-oracle02
  • If the computer name matches the allowed host, it will try to copy a file from the following network share:
    • \\{BLOCKED}m.local\SYSVOL\fpc2_dom.local\Policies → inaccessible

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 19.624.04
FIRST VSAPI PATTERN DATE: 01 Oct 2024
VSAPI OPR PATTERN File: 19.625.00
VSAPI OPR PATTERN Date: 02 Oct 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

Search and delete this file

[ 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.
  •  %User Temp%\{random alphanumeric}.{random alphanumeric}.ps1 
  • %User Temp%\{random alphanumeric}.{random alphanumeric}.psm1
  • %ProgramData%\loader.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as Trojan.PS1.KILLAV.B. 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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