Trojan.Win32.GULOADER.UVFTIP

April 08, 2022
 Analysis by: Bren Matthew Ebriega
 ALIASES:

EUR:Trojan-Downloader.Win32.GuLoader.gen (KASPERSKY); Trojan:Win32/NSISInject.EE!MTB (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • 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.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

166,200 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

01 Feb 2022

Payload:

Connects to URLs/IPs, 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\racehorse.dat → Shellcode to be decrypted and executed.
  • %User Temp\secur32.dll
  • %User Temp\sxsstore.dll
  • %User Temp\nst{Hex}.tmp\System.dll

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • https://www.{BLOCKED}arket.com/2022file_izNuHdosu25.bin

As of this writing, the said sites are inaccessible.

Other Details

This Trojan does the following:

  • It does not proceed to its routines if it detects it is running in a virtual environment or an environment using virtualization.
  • Terminates itself if there are less than 12 processes running found in the system.

It checks if the following virtual machine or sandbox related module(s) is loaded in the affected system:

  • %Program Files%\Qemu-ga\qemu-ga.exe
  • %Program Files%\qga\qga.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It does not proceed to its malicious routine if it detects that it is being debugged.

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

17.358.05

FIRST VSAPI PATTERN DATE:

03 Feb 2022

VSAPI OPR PATTERN File:

17.359.00

VSAPI OPR PATTERN Date:

04 Feb 2022

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • TROJ.Win32.TRX.XXPE50FSX020

Step 2

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 3

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 4

Identify and terminate files detected as Trojan.Win32.GULOADER.UVFTIP

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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 Temp\racehorse.dat
  • %User Temp\secur32.dll
  • %User Temp\sxsstore.dll
  • %User Temp\nst{Hex}.tmp\System.dll

Step 6

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