PE_WAMGIN.D
Backdoor:Win32/VB (Microsoft); Generic BackDoor.k (McAfee); W32.Wamgin (Symantec); Backdoor.Win32.VB.arg (Kaspersky); Worm.WinNT.Lurka.a (v) (Sunbelt); I-Worm/Brontok.AA (AVG)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: File infector
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This file infector 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
Arrival Details
This file infector arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Autostart Technique
This file infector modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "explorer.exe %Windows%\SMSS.EXE"
(Note: The default value data of the said registry entry is Explorer.exe.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe,%Windows%\SMSS.EXE"
(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)
Other System Modifications
This file infector deletes the following files:
- %Temp%\scs6.tmp
- %Temp%\scs9.tmp
(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)
It deletes the following folders:
- %Windows%\SMSS.EXE
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
Dropping Routine
This file infector drops the following files:
- %System Root%\dntboot.bin
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
This report is generated via an automated analysis system.
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
Identify and delete files detected as PE_WAMGIN.D using either the Startup Disk or Recovery Console
Step 3
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\Winlogon
- From: Shell = "explorer.exe %Windows%\SMSS.EXE"
To: Shell = ""Explorer.exe""
- From: Shell = "explorer.exe %Windows%\SMSS.EXE"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: Userinit = "%System%\userinit.exe,%Windows%\SMSS.EXE"
To: Userinit = ""%Windows%\system32\userinit.exe,""
- From: Userinit = "%System%\userinit.exe,%Windows%\SMSS.EXE"
Step 4
Search and delete this file
- %System Root%\dntboot.bin
Step 5
Scan your computer with your Trend Micro product to clean files detected as PE_WAMGIN.D. 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.
- %Temp%\scs6.tmp
- %Temp%\scs9.tmp
Did this description help? Tell us how we did.