This backdoor may arrive bundled with malware packages as a malware component.
It executes commands from a remote malicious user, effectively compromising the affected system.
Arrival Details
This backdoor may arrive bundled with malware packages as a malware component.
Installation
This backdoor drops the following component file(s):
- %Program Files%\Microsoft.NET\RedistList\KunlunPlatform.exe - non-malicious file used to load BKDR_PLUGX.DUKPF
- %Program Files%\Microsoft.NET\RedistList\DefMgr.dll - detected as BKDR_PLUGX.DUKPF
- %Program Files%\Microsoft.NET\RedistList\DefMgr.dll.rom - - detected as BKDR_PLUGX.ENC
(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)
It is injected into the following processes running in memory:
Autostart Technique
This backdoor registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\clr_optimization_v4.0.30512_32
ImageName = %Program Files%\Microsoft.NET\RedistList\KunlunPlatform.exe
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\clr_optimization_v4.0.30512_32
DisplayName = Microsoft .NET Framework NGEN v4.0.30512_X86
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\clr_optimization_v4.0.30512_32
Microsoft .NET Framework NGEN v4.0.30512_X86 = Description
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Manage files, registries, services and directories
- Log keystrokes and active window
- Restart/Reboot/Shutdown system
- Enumerate processes
- Terminate processes
- Get drive information
- Enumerate network resources
- Set TCP connection state
- Lock workstation
- Display a message box
- Perfrom port mapping
- Capture screen
- Perform remote shell
Process Termination
This backdoor terminates the following processes if found running in the affected system's memory:
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 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
[ Learn More ]
[ back ]
To restart in Safe Mode:
• For Windows 2000 users
- Restart your computer.
- Press F8 when you see the Starting Windows bar at the bottom of the screen.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows XP users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Windows Advanced Options menu does not appear, try restarting then pressing F8 several times when the POST screen appears.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows Server 2003 users
- Restart your computer.
- Press F8 after Windows starts up. If the Windows Advanced Options menu does not appear, try restarting again and pressing F8 several times afterward.
- On the Windows Advanced Option menu, use the arrow keys to select Safe Mode then press Enter.
• For Windows Vista, Windows 7, and Windows Server 2008 users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Advanced Boot Options menu does not appear, try restarting and then pressing F8 several times after the POST screen is displayed.
- On the Advanced Boot Options menu, use the arrow keys to select the Safe Mode option, and then press Enter.
• For Windows 8, Windows 8.1, and Windows Server 2012 users
- Access the Charms bar by moving your mouse pointer to the upper right corner of the screen.
- Move your mouse pointer down and click Settings>Change your PC Settings.
- In the left panel, click General.
- In the right panel, scroll down to the bottom to find the Advanced startup section, then click the Restart now button and wait for the system to restart.
- In the Advanced Startup menu, click Troubleshoot>Advanced Options>Startup Settings>Restart and wait for the system to restart.
- In the Startup Settings menu, press 4 to enable safe mode.
Step 4
Delete this registry key
[ Learn More ]
[ back ]
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.
- HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\clr_optimization_v4.0.30512_32
To delete registry keys this malware/grayware created:
- Open Registry Editor. To do this:
» For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run, type regedit in the text box provided, and then press Enter.
» For Windows Vista, Windows 7, and Windows Server 2008 users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, Windows 8.1, and Windows Server 2012 users, right-click on the lower left corner of the screen, click Run, type regedit in the text box provided, and then press Enter. - HKEY_LOCAL_MACHINE\\SYSTEM\\ControlSet001\\Services\\clr_optimization_v4.0.30512_32
- Close Registry Editor.
Step 5
Search and delete this file
[ Learn More ]
[ back ]
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.
- %Program Files%\Microsoft.NET\RedistList\KunlunPlatform.exe
- %Program Files%\Microsoft.NET\RedistList\DefMgr.dll
- %Program Files%\Microsoft.NET\RedistList\DefMgr.dll.rom
To manually delete a malware/grayware file from an affected system:
• For Windows 2000, Windows XP, and Windows Server 2003:
- Right-click Start then click Search....
- In the File name* input box, type the following:
- %Program Files%\Microsoft.NET\RedistList\KunlunPlatform.exe
- %Program Files%\Microsoft.NET\RedistList\DefMgr.dll
- %Program Files%\Microsoft.NET\RedistList\DefMgr.dll.rom
- In the Look In drop-down list, select My Computer then press Enter.
- Once located, select the file then press SHIFT+DELETE to delete it.
*Note: The file name input box title varies depending on the Windows version (e.g. Search for files or folders named or All or part of the file name.).
• For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:
- Open a Windows Explorer window.
- For Windows Vista, 7, and Server 2008 users, click Start>Computer.
- For Windows 8, 8.1, 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:
- %Program Files%\Microsoft.NET\RedistList\KunlunPlatform.exe
- %Program Files%\Microsoft.NET\RedistList\DefMgr.dll
- %Program Files%\Microsoft.NET\RedistList\DefMgr.dll.rom
- Once located, select the file then press SHIFT+DELETE to delete it.
*Note: Read the following Microsoft page if these steps do not work on Windows 7.
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_PLUGX.DUKPF. 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.
