TROJ_PROVIS.BR
Windows 2000, Windows, XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted: No
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.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
569,344 bytes
EXE
Yes
14 Nov 2011
Drops files, Connects to URLs/IPs
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%\ploqk1c7wjk.txt
(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 drops the following copies of itself into the affected system:
- %User Temp%\{random filename}.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.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random filename} = "%Program Files%\{random folder}\{random filename}.exe"
Other System Modifications
This Trojan adds the following registry keys as part of its installation routine:
HKEY_CURRENT_USER\Software\VB and VBA Program Settings
Other Details
This Trojan deletes the initially executed copy of itself
NOTES:
It searches for .EXE files in the %Program Files% directory and lists all files found in the file %User Temp%\ploqk1c7wjk.txt. It then drops a copy of itself to the folders of files found using random filename. It attempts to access the following sites to download possibly malicious files:
- http://{random numbers}.{BLOCKED}ot.com/
- http://{random numbers}.{BLOCKED}o.3322.org/
However, the URLs are inaccessible as of this writing.
SOLUTION
9.200
8.572.02
14 Nov 2011
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 2
Scan your computer with your Trend Micro product and note files detected as TROJ_PROVIS.BR
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
- {random filename} = %Program Files%\{random folder}\{random filename}.exe
- {random filename} = %Program Files%\{random folder}\{random filename}.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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_CURRENT_USER\Software
- VB and VBA Program Settings
- VB and VBA Program Settings
Step 6
Search and delete this file
- %User Temp%\ploqk1c7wjk.txt
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_PROVIS.BR. 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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