BKDR_PLUGX.MMC
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It does not have any propagation routine.
It executes commands from a remote malicious user, effectively compromising the affected system. However, as of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
Arrival Details
This backdoor 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 backdoor drops the following copies of itself into the affected system and executes them:
- %Windows%\WPDShexplayProxy.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
It drops the following non-malicious files:
- %All Users Profile%\DRM\xs\{random characters}
(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)
It adds the following processes:
- iexplore.exe
It creates the following folders:
- %All Users Profile%\DRM\xs
(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Global\{random}
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WPDShexplayProxy = "%Windows%\WPDShexplayProxy.exe"
Other System Modifications
This backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
User Agent
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
User Agent\Post Platform
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
5.0\User Agent
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
5.0\User Agent\Post Platform
Propagation
This backdoor does not have any propagation routine.
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Copy, move, rename, delete files
- Create directories
- Create files
- Enumerate files
- Execute files
- Get drive information
- Get file information
- Open and modify files
- Log keystrokes and active window
- Enumerate TCP and UDP connections
- Enumerate network resources
- Set TCP connection state
- Lock workstation
- Log off user
- Restart/Reboot/Shutdown system
- Display a message box
- Perfrom port mapping
- Enumerate processes
- Get process information
- Terminate processes
- Enumerate registry keys
- Create registry keys
- Delete registry keys
- Copy registry keys
- Enumerate registry entries
- Modify registry entries
- Delete registry values
- Screen capture
- Delete services
- Enumerate services
- Get service information
- Modify services
- Start services
- Perform remote shell
- Host Telnet server
- Connect to a database server and execute SQL statement
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- http://{BLOCKED}a.{BLOCKED}app.com/{random generated value}
However, as of this writing, the said sites are inaccessible.
NOTES:
It does not have rootkit capabilities.
It does not exploit any vulnerability.
SOLUTION
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
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- WPDShexplayProxy = "%Windows%\WPDShexplayProxy.exe"
- WPDShexplayProxy = "%Windows%\WPDShexplayProxy.exe"
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\Microsoft\Windows\CurrentVersion\Internet Settings
- User Agent
- User Agent
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\5.0
- User Agent
- User Agent
Step 6
Search and delete these folders
- %All Users Profile%\DRM\xs
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_PLUGX.MMC. 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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