TROJ_AGENT.WST
TrojanDropper:Win32/Rootkit.AFH (Microsoft); Generic PWS.y (McAfee); Downloader.Trojan (Symantec); PAK:UPX, Trojan-GameThief.Win32.OnLineGames.ef (Kaspersky); Trojan.Win32.Packer.UPX-ScramblerRCv1.x (ep) (Sunbelt)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
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.
It deletes itself after execution.
TECHNICAL DETAILS
36,864 bytes
EXE
No
14 Oct 2012
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.
Other System Modifications
This Trojan deletes the following files:
- %System%\verclsid.exe
- %System%\dllcache\verclsid.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
It adds the following registry keys:
HKEY_CLASSES_ROOT\CLSID\{1A404685-7563-4d02-B0F6-58B308A406A9}
HKEY_CLASSES_ROOT\CLSID\{1A404685-7563-4d02-B0F6-58B308A406A9}\
InProcServer32
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Desktop
RXMRU = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1A404685-7563-4d02-B0F6-58B308A406A9}\InProcServer32
ThreadingModel = "Apartment"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{1A404685-7563-4d02-B0F6-58B308A406A9}\InProcServer32
Temp = "{malware path and file name}"
Dropping Routine
This Trojan drops the following files:
- %Program Files%\vmware\vmware tools\wpnufser.dll
- %Program Files%\vmware\vmware tools\dvdamkjs.dll
- %Program Files%\vmware\vmware tools\tfrhlmwg.dll
- %Program Files%\messenger\adicszts.dll
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)
Other Details
This Trojan deletes itself after execution.
This report is generated via an automated analysis system.
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 2
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_CLASSES_ROOT\CLSID
- {1A404685-7563-4d02-B0F6-58B308A406A9}
- In HKEY_CLASSES_ROOT\CLSID\{1A404685-7563-4d02-B0F6-58B308A406A9}
- InProcServer32
Step 3
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\Explorer\Desktop
- RXMRU = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1A404685-7563-4d02-B0F6-58B308A406A9}\InProcServer32
- ThreadingModel = "Apartment"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{1A404685-7563-4d02-B0F6-58B308A406A9}\InProcServer32
- Temp = "{malware path and file name}"
Step 4
Search and delete these files
- %Program Files%\vmware\vmware tools\wpnufser.dll
- %Program Files%\vmware\vmware tools\dvdamkjs.dll
- %Program Files%\vmware\vmware tools\tfrhlmwg.dll
- %Program Files%\messenger\adicszts.dll
Step 5
Scan your computer with your Trend Micro product to delete files detected as TROJ_AGENT.WST. 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.
Step 6
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %System%\verclsid.exe
- %System%\dllcache\verclsid.exe
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