WORM_BRONTOK.IC
Virus:Win32/VB.CD (Microsoft); W32/Rontokbro.gen@MM (McAfee); W32.Olderdata (Symantec); Virus.Win32.VB.cd (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Ciador.VB.A (FSecure)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
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
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.
Other System Modifications
This worm deletes the following files:
- %Temp%\scs1.tmp
- %Temp%\scs2.tmp
(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp or C:\WINNT\Temp.)
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\advapi32.dll[MofResourceName] = "LowDateTime:-878345984,HighDateTime:29653303***Binary mof compiled successfully"
(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\ACPI.sys[ACPIMOFResource] = "LowDateTime:-1893836544,HighDateTime:29653288***Binary mof compiled successfully"
(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\mssmbios.sys[MofResource] = "LowDateTime:246686720,HighDateTime:29653305***Binary mof compiled successfully"
(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\intelppm.sys[PROCESSORWMI] = "LowDateTime:1716098048,HighDateTime:29653287***Binary mof compiled successfully"
(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\DRIVERS\ipnat.sys[IPNATMofResource] = "LowDateTime:741130752,HighDateTime:29653288***Binary mof compiled successfully"
(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
WBEM\WDM
%System%\Drivers\HTTP.sys[UlMofResource] = "LowDateTime:-2038869248,HighDateTime:29653287***Binary mof compiled successfully"
(Note: The default value data of the said registry entry is LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully.)
Dropping Routine
This worm drops the following files:
- %User Temp%\taskmgr.tme
- %User Temp%\TASKMGR.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.)
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
Restore this modified 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\WBEM\WDM
- From: %System%\advapi32.dll[MofResourceName] = "LowDateTime:-878345984,HighDateTime:29653303***Binary mof compiled successfully"
To: %System%\advapi32.dll[MofResourceName] = "LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully"
- From: %System%\advapi32.dll[MofResourceName] = "LowDateTime:-878345984,HighDateTime:29653303***Binary mof compiled successfully"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
- From: %System%\DRIVERS\ACPI.sys[ACPIMOFResource] = "LowDateTime:-1893836544,HighDateTime:29653288***Binary mof compiled successfully"
To: %System%\DRIVERS\ACPI.sys[ACPIMOFResource] = "LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully"
- From: %System%\DRIVERS\ACPI.sys[ACPIMOFResource] = "LowDateTime:-1893836544,HighDateTime:29653288***Binary mof compiled successfully"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
- From: %System%\DRIVERS\mssmbios.sys[MofResource] = "LowDateTime:246686720,HighDateTime:29653305***Binary mof compiled successfully"
To: %System%\DRIVERS\mssmbios.sys[MofResource] = "LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully"
- From: %System%\DRIVERS\mssmbios.sys[MofResource] = "LowDateTime:246686720,HighDateTime:29653305***Binary mof compiled successfully"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
- From: %System%\DRIVERS\intelppm.sys[PROCESSORWMI] = "LowDateTime:1716098048,HighDateTime:29653287***Binary mof compiled successfully"
To: %System%\DRIVERS\intelppm.sys[PROCESSORWMI] = "LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully"
- From: %System%\DRIVERS\intelppm.sys[PROCESSORWMI] = "LowDateTime:1716098048,HighDateTime:29653287***Binary mof compiled successfully"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
- From: %System%\DRIVERS\ipnat.sys[IPNATMofResource] = "LowDateTime:741130752,HighDateTime:29653288***Binary mof compiled successfully"
To: %System%\DRIVERS\ipnat.sys[IPNATMofResource] = "LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully"
- From: %System%\DRIVERS\ipnat.sys[IPNATMofResource] = "LowDateTime:741130752,HighDateTime:29653288***Binary mof compiled successfully"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WBEM\WDM
- From: %System%\Drivers\HTTP.sys[UlMofResource] = "LowDateTime:-2038869248,HighDateTime:29653287***Binary mof compiled successfully"
To: %System%\Drivers\HTTP.sys[UlMofResource] = "LowDateTime:-1618731008,HighDateTime:29653597***Binary mof compiled successfully"
- From: %System%\Drivers\HTTP.sys[UlMofResource] = "LowDateTime:-2038869248,HighDateTime:29653287***Binary mof compiled successfully"
Step 3
Search and delete these files
- %User Temp%\taskmgr.tme
- %User Temp%\TASKMGR.TXT
Step 4
Scan your computer with your Trend Micro product to delete files detected as WORM_BRONTOK.IC. 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%\scs1.tmp
- %Temp%\scs2.tmp
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