Analysis by: Maria Emreen Viray
ALIASES:

Trojan:Win32/GuLoader.AM!MTB (MICROSOFT)

 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.

It terminates itself if it detects it is being run in a virtual environment.

  TECHNICAL DETAILS

File Size: 1,245,184 bytes
File Type: Other
Memory Resident: No
Initial Samples Received Date: 01 Jul 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 Profile%\Arrhythmia.ini
  • %User Temp%\ns{random}.tmp\System.dll
  • %Application Data%\Luftrumsorganisation78\petrogale.UNP
  • %User Profile%\Rigssprogstalendes.ini

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} 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).. %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 creates the following folders:

  • %User Temp%\ns{random}.tmp
  • %Application Data%\Luftrumsorganisation78

(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).. %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).)

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\PRINCIPFASTERES\
Selvbebrejdelsen
Kvilibristernes17 = %WINDIR%\Hoofy.Vag

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
Encephalomalaxis
Forebygg = 0

HKEY_CURRENT_USER\Software\Chlorocarbonate\
Begrebernes
Underbevidstheders = %WINDIR%\Assassinated.Vin

HKEY_LOCAL_MACHINE\SOFTWARE\Doterer\
Unprotectable
poleremidler = Haandtaskens

Other Details

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Chlorocarbonate

HKEY_CURRENT_USER\Software\Chlorocarbonate\
Begrebernes

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
Encephalomalaxis

HKEY_LOCAL_MACHINE\SOFTWARE\Doterer

HKEY_LOCAL_MACHINE\SOFTWARE\Doterer\
Unprotectable

HKEY_LOCAL_MACHINE\SOFTWARE\PRINCIPFASTERES

HKEY_LOCAL_MACHINE\SOFTWARE\PRINCIPFASTERES\
Selvbebrejdelsen

It terminates itself if it detects it is being run in a virtual environment.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 17.660.03
FIRST VSAPI PATTERN DATE: 01 Jul 2022
VSAPI OPR PATTERN File: 17.661.00
VSAPI OPR PATTERN Date: 02 Jul 2022

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_LOCAL_MACHINE\SOFTWARE\PRINCIPFASTERES\Selvbebrejdelsen
    • Kvilibristernes17 = %WINDIR%\Hoofy.Vag
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\Encephalomalaxis
    • Forebygg = 0
  • In HKEY_CURRENT_USER\Software\Chlorocarbonate\Begrebernes
    • Underbevidstheders = %WINDIR%\Assassinated.Vin
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Doterer\Unprotectable
    • poleremidler = Haandtaskens

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\Chlorocarbonate
  • In HKEY_CURRENT_USER\Software\Chlorocarbonate\Begrebernes
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\Encephalomalaxis
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Doterer
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Doterer\Unprotectable
  • In HKEY_LOCAL_MACHINE\SOFTWARE\PRINCIPFASTERES
  • In HKEY_LOCAL_MACHINE\SOFTWARE\PRINCIPFASTERES\Selvbebrejdelsen

Step 5

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 Profile%\Arrhythmia.ini
  • %User Temp%\ns{random}.tmp\System.dll
  • %Application Data%\Luftrumsorganisation78\petrogale.UNP
  • %User Profile%\Rigssprogstalendes.ini

Step 6

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Temp%\ns{random}.tmp
  • %Application Data%\Luftrumsorganisation78

Step 7

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.GULOADER.UVFTKK. 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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