BKDR_PROXY.TPA
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
Dropped by other malware
This backdoor may be dropped by other malware.
It executes commands from a remote malicious user, effectively compromising the affected system.
TECHNICAL DETAILS
57,334 bytes
EXE
Yes
25 Aug 2012
Compromises system security
Arrival Details
This backdoor may be dropped by the following malware:
Installation
This backdoor drops the following copies of itself into the affected system:
- %User Temp%\517\wupdmgr.exe
(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, XP, and Server 2003.)
It creates the following folders:
- %User Temp%\517
(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, XP, and Server 2003.)
Autostart Technique
This backdoor modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
User Shell Folders
Common Startup = "%User Temp%\517"
(Note: The default value data of the said registry entry is %ALLUSERSPROFILE%\StartMenu\Programs\Startup.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Shell Folders
Common Startup = "%User Temp%\517"
(Note: The default value data of the said registry entry is %ALLUSERSPROFILE%\StartMenu\Programs\Startup.)
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Create processes
- Download files
- Manage files
- Perform remote shell
- Search and upload files
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- http://www.{BLOCKED}s.com:80/index.html
SOLUTION
9.200
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 3
Restart in Safe Mode
Step 4
Restore this modified 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\Explorer\Shell Folders
- From: Common Startup = "%User Temp%\517"
To: Common Startup = %ALLUSERSPROFILE%\StartMenu\Programs\Startup
- From: Common Startup = "%User Temp%\517"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
- From: Common Startup = "%User Temp%\517"
To: Common Startup = %ALLUSERSPROFILE%\StartMenu\Programs\Startup
- From: Common Startup = "%User Temp%\517"
Step 5
Search and delete these folders
- %User Temp%\517
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_PROXY.TPA. 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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