Analysis by: Glaizel Mallari
 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

File Size: 507,594 bytes
File Type: EXE
Initial Samples Received Date: 22 Apr 2026

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%\grundoperationer\diplomatiet
  • %User Profile%\grundoperationer\Bonfires\Hvirvlernes.txt
  • %User Profile%\grundoperationer\Bonfires\Troupes
  • %User Profile%\grundoperationer\Bonfires\guying.ini
  • %User Profile%\grundoperationer\Bonfires\helsebringende.txt
  • %User Profile%\grundoperationer\Bonfires\incoming.sti
  • %User Profile%\grundoperationer\Bonfires\okkerfarvet.jpg
  • %User Profile%\grundoperationer\Bonfires\posrens.txt
  • %User Profile%\grundoperationer\Bonfires\skakker.txt
  • %User Profile%\grundoperationer\Bonfires\storkeredes.txt
  • %User Profile%\grundoperationer\Transfusionskanylers\xylocarps.jpg
  • %User Profile%\restarter.ini
  • %User Temp%\nsdD1D0.tmp\System.dll

(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).)

It drops the following copies of itself into the affected system:

  • %ProgramData%\Remcos\remcos.exe

(Note: %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:

  • {Malware Path}\{Malware File Name}.exe
  • %ProgramData%\Remcos\remcos.exe

(Note: %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.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Rmc-O5UVJF = %ProgramData%\Remcos\remcos.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Rmc-O5UVJF = %ProgramData%\Remcos\remcos.exe

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\nsnCD2D.tmp
  • %User Temp%\nsi62A8.tmp

(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 registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\thatness

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\thatness\
taktreguleringsaftalerne

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\thatness\
taktreguleringsaftalerne
mistery data = %System Root%\verdenshjrner\salvendes.gif

HKEY_CURRENT_USER\Software\Microsoft\
Windows\ribonucleoprotein
frisurers = 0

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Gallers
Miniaturizes = FF E0 11 60

HKEY_CURRENT_USER\Software\Microsoft\
Windows\pemicans

HKEY_CURRENT_USER\Software\Microsoft\
Windows\pemicans\standpoint

HKEY_CURRENT_USER\Software\Microsoft\
Windows\pemicans\standpoint
sieben = 0

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Bilforsikringer
pakkelsningernes = 2F 76 C5

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\phlebotomiz
kuldegysnings = %System Root%\fupmagerne\beskylder.jpg

Other Details

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Rmc-O5UVJF

It connects to the following possibly malicious URL:

  • http://drive.{BLOCKED}e.com:443
  • http://drive.usercontent.{BLOCKED}e.com:443
  • http://ctldl.{BLOCKED}pdate.com/msdownload/update/v3/static/trustedr/en/disallowedcertstl.cab?76b7bfccba1f0bce
  • http://ctldl.{BLOCKED}pdate.com/msdownload/update/v3/static/trustedr/en/authrootstl.cab?79ae797e7524f609
  • https://drive.{BLOCKED}e.com/uc?export=download&id=1FlywZu1zEZ9o-f1IQe3FilUQqYUMsody
  • https://drive.usercontent.{BLOCKED}e.com/download?id=1FlywZu1zEZ9o-f1IQe3FilUQqYUMsody&export=download

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 20.901.00
FIRST VSAPI PATTERN DATE: 21 Apr 2026
VSAPI OPR PATTERN File: 20.901.00
VSAPI OPR PATTERN Date: 22 Apr 2026

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.XXPE50FSX070

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

Restart in Safe Mode

[ Learn More ]

Step 5

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_USER\Software\Microsoft\Windows\CurrentVersion\thatness\taktreguleringsaftalerne
    • mistery = %System Root%\verdenshjrner\salvendes.gif
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\ribonucleoprotein
    • frisurers = 0
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Gallers
    • Miniaturizes = FF E0 11 60
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\pemicans\standpoint
    • sieben = 0
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Bilforsikringer
    • pakkelsningernes = 2F 76 C5
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\phlebotomize
    • kuldegysnings = %System Root%\fupmagerne\beskylder.jpg
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Rmc-O5UVJF = %ProgramData%\Remcos\remcos.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Rmc-O5UVJF = %ProgramData%\Remcos\remcos.exe

Step 6

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\
    • Rmc-O5UVJF

Step 7

Search and delete these files

[ 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% \grundoperationer\diplomatiet
  • %User Profile% \grundoperationer\Bonfires\Hvirvlernes.txt
  • %User Profile% \grundoperationer\Bonfires\Troupes
  • %User Profile% \grundoperationer\Bonfires\guying.ini
  • %User Profile% \grundoperationer\Bonfires\helsebringende.txt
  • %User Profile% \grundoperationer\Bonfires\incoming.sti
  • %User Profile% \grundoperationer\Bonfires\okkerfarvet.jpg
  • %User Profile% \grundoperationer\Bonfires\posrens.txt
  • %User Profile% \grundoperationer\Bonfires\skakker.txt
  • %User Profile% \grundoperationer\Bonfires\storkeredes.txt
  • %User Profile% \grundoperationer\Transfusionskanylers\xylocarps.jpg
  • %User Profile% \restarter.ini
  • %User Temp% \nsdD1D0.tmp\System.dll

Step 8

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

Step 9

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.Win32.GULOADER.YXGDVZ. 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 this Knowledge Base page for more information.


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