WORM_KLEZ.AI
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
TECHNICAL DETAILS
185,728 bytes
EXE
No
07 Dec 2013
Arrival Details
This worm 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 worm drops the following copies of itself into the affected system:
- %System%\Winkqt.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Other System Modifications
This worm deletes the following files:
- %Temp%\Mxv4.tmp
- %Temp%\BpxA.tmp
- %Temp%\VgrF.tmp
- %Temp%\Fbc13.tmp
- %Temp%\Fbc13.exe
- %Temp%\Iy16.tmp
- %Temp%\Iy16.exe
- %Temp%\Pcz19.tmp
- %Temp%\Pcz19.exe
- %Temp%\Vvk1C.tmp
- %Temp%\Vvk1C.exe
- %Temp%\Uuc1F.tmp
- %Temp%\Qza24.tmp
- %Temp%\Qza24.exe
- %Temp%\Zp27.tmp
- %Temp%\Zp27.exe
- %Temp%\Cah2A.tmp
- %Temp%\Cah2A.exe
(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Windows
AppInit_DLLs = "Wqk.dll"
Dropping Routine
This worm drops the following files:
- %Temp%\Mxv4.exe
- %Program Files%\Adobe\Reader 10.0\Reader\AcroRd32.wst
- %Program Files%\Messenger\msmsgs.gyk
- %System%\Winkqt.exe
- %Temp%\BpxA.exe
- %Program Files%\Adobe\Reader 10.0\Reader\AcroRd32.exe
- %Temp%\VgrF.exe
- %Temp%\Fbc13.exe
- %Temp%\Iy16.exe
- %Temp%\Pcz19.exe
- %Temp%\Vvk1C.exe
- %Temp%\Uuc1F.exe
- %Program Files%\Messenger\msmsgs.exe
- %Temp%\Qza24.exe
- %Temp%\Zp27.exe
- %Temp%\Cah2A.exe
- %System%\Wqk.dll
(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).. %System% is the Windows system folder, which is usually C:\Windows\System32.)
This report is generated via an automated analysis system.
SOLUTION
9.300
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
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
- AppInit_DLLs = "Wqk.dll"
Step 3
Search and delete these components
- %Temp%\Mxv4.exe
- %Program Files%\Adobe\Reader 10.0\Reader\AcroRd32.wst
- %Program Files%\Messenger\msmsgs.gyk
- %System%\Winkqt.exe
- %Temp%\BpxA.exe
- %Program Files%\Adobe\Reader 10.0\Reader\AcroRd32.exe
- %Temp%\VgrF.exe
- %Temp%\Fbc13.exe
- %Temp%\Iy16.exe
- %Temp%\Pcz19.exe
- %Temp%\Vvk1C.exe
- %Temp%\Uuc1F.exe
- %Program Files%\Messenger\msmsgs.exe
- %Temp%\Qza24.exe
- %Temp%\Zp27.exe
- %Temp%\Cah2A.exe
- %System%\Wqk.dll
Step 4
Scan your computer with your Trend Micro product to delete files detected as WORM_KLEZ.AI. 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 5
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.
- %Temp%\Mxv4.tmp
- %Temp%\BpxA.tmp
- %Temp%\VgrF.tmp
- %Temp%\Fbc13.tmp
- %Temp%\Fbc13.exe
- %Temp%\Iy16.tmp
- %Temp%\Iy16.exe
- %Temp%\Pcz19.tmp
- %Temp%\Pcz19.exe
- %Temp%\Vvk1C.tmp
- %Temp%\Vvk1C.exe
- %Temp%\Uuc1F.tmp
- %Temp%\Qza24.tmp
- %Temp%\Qza24.exe
- %Temp%\Zp27.tmp
- %Temp%\Zp27.exe
- %Temp%\Cah2A.tmp
- %Temp%\Cah2A.exe
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