BKDR_SHIZ.CH
Backdoor:Win32/Simda.gen!B (Microsoft); Generic BackDoor.vu (McAfee); Backdoor.Trojan (Symantec); Backdoor.Win32.Shiz.ajyp (Kaspersky); ERROR (Sunbelt); Trojan.Generic.KDV.486815 (FSecure)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This backdoor 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 backdoor 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 backdoor drops the following copies of itself into the affected system:
- %Windows%\apppatch\bgmdmf.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
userinit = "%Windows%\apppatch\bgmdmf.exe"
Other System Modifications
This backdoor deletes the following files:
- %User Temp%\1.tmp
(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 adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
68ad0fd0 = {random characters}
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
userinit = "%System%\userinit.exe,%Windows%\apppatch\bgmdmf.exe,"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
System = "%Windows%\apppatch\bgmdmf.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
load = "%Windows%\apppatch\bgmdmf.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
run = "%Windows%\apppatch\bgmdmf.exe"
Dropping Routine
This backdoor drops the following files:
- %Windows%\apppatch\bgmdmf.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
This report is generated via an automated analysis system.
SOLUTION
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
Restart in Safe Mode
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- userinit="%Windows%\apppatch\bgmdmf.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- 68ad0fd0={random characters}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- userinit="%System%\userinit.exe,%Windows%\apppatch\bgmdmf.exe,"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- System="%Windows%\apppatch\bgmdmf.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
- load="%Windows%\apppatch\bgmdmf.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
- run="%Windows%\apppatch\bgmdmf.exe"
Step 4
Search and delete this file
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_SHIZ.CH. 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. %User Temp%\1.tmp
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