WORM_BRONTOK.CIA
Worm:Win32/Brontok.FFV (Microsoft); W32/Rontokbro.worm (McAfee); PAK:PE_Patch (Kaspersky); Virus.Win32.Virut.ce (v) (Sunbelt)
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
203,776 bytes
EXE
Yes
16 Jun 2012
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 creates the following folders:
- %System%\dllchache
(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.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Blank AntiViri = "%System Root%\AUT0EXEC.BAT StartUp"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Secure64 = "%System%\dllcache\Regedit32.com StartUp"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Secure32 = "%System%\dllcache\Shell32.com StartUp"
It modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe, %System%\M5VBVM60.EXE StartUp"
(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)
Other System Modifications
This worm adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CabinetState
FullPathAddress = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CabinetState
FullPath = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "1"
(Note: The default value data of the said registry entry is 2.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = "1"
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\SafeBoot
AlternateShell = "%System Root%\AUT0EXEC.BAT StartUp"
(Note: The default value data of the said registry entry is cmd.exe.)
Dropping Routine
This worm drops the following files:
- %System Root%\(Read Me)Pendekar Blank.txt
- %System%\dllChache\msvbvm60.dll
- %System Root%\msvbvm60.dll
- %System%\dllcache\msvbvm60.dll
- %System%\dllChache\Empty.jpg
- %System%\dllChache\Blank.doc
- %System%\dllChache\Zero.txt
- %System%\dllChache\Hole.zip
- %System%\dllChache\Unoccupied.reg
- %System Root%\AUT0EXEC.BAT
- %System%\rund1132.exe
- %System%\dllcache\Regedit32.com
- %System%\dllcache\Shell32.com
- %System%\M5VBVM60.EXE
- %System%.exe
- %System%\dllchache.exe
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
Identify and delete files detected as WORM_BRONTOK.CIA using either the Startup Disk or Recovery Console
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\Run
- Blank AntiViri = "%System Root%\AUT0EXEC.BAT StartUp"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Secure64 = "%System%\dllcache\Regedit32.com StartUp"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Secure32 = "%System%\dllcache\Shell32.com StartUp"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\CabinetState
- FullPathAddress = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- ShowSuperHidden = "0"
Step 4
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\CabinetState
- FullPath = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: Hidden = "1"
To: Hidden = ""2""
- From: Hidden = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: HideFileExt = "1"
To: HideFileExt = ""1""
- From: HideFileExt = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\SafeBoot
- From: AlternateShell = "%System Root%\AUT0EXEC.BAT StartUp"
To: AlternateShell = ""cmd.exe""
- From: AlternateShell = "%System Root%\AUT0EXEC.BAT StartUp"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: Userinit = "%System%\userinit.exe, %System%\M5VBVM60.EXE StartUp"
To: Userinit = ""%Windows%\system32\userinit.exe,""
- From: Userinit = "%System%\userinit.exe, %System%\M5VBVM60.EXE StartUp"
Step 5
Search and delete these files
- %System Root%\(Read Me)Pendekar Blank.txt
- %System%\dllChache\msvbvm60.dll
- %System Root%\msvbvm60.dll
- %System%\dllcache\msvbvm60.dll
- %System%\dllChache\Empty.jpg
- %System%\dllChache\Blank.doc
- %System%\dllChache\Zero.txt
- %System%\dllChache\Hole.zip
- %System%\dllChache\Unoccupied.reg
- %System Root%\AUT0EXEC.BAT
- %System%\rund1132.exe
- %System%\dllcache\Regedit32.com
- %System%\dllcache\Shell32.com
- %System%\M5VBVM60.EXE
- %System%.exe
- %System%\dllchache.exe
Step 6
Search and delete this folder
- %System%\dllchache
Step 7
Scan your computer with your Trend Micro product to delete files detected as WORM_BRONTOK.CIA. 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.
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