W32/Brontok-BU

Category: Viruses and Spyware Protection available since:11 Oct 2006 00:00:00 (GMT)
Type: Win32 worm Last Updated:11 Oct 2006 00:00:00 (GMT)
Prevalence: Small Number of Reports

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W32/Brontok-BU is a worm for the Windows platform.


When first run W32/Brontok-BU copies itself to:

<Startup>\Empty.pif
<User>\Local Settings\Application Data\windows\csrss.exe
<User>\Local Settings\Application Data\windows\lsass.exe
<User>\Local Settings\Application Data\windows\services.exe
<User>\Local Settings\Application Data\windows\smss.exe
<User>\Local Settings\Application Data\windows\winlogon.exe
\RosTika.exe
<Windows>\RosTika.exe
<System>\shell.exe

and creates the file <Windows>\biakKITE.txt.

The following registry entries are created to run W32/Brontok-BU on startup:

HKCU\Software\Microsoft\Windows\CurrentVersion\Run
RosTika
<Windows>\RosTika.exe

HKCU\Software\Microsoft\Windows\CurrentVersion\Run
Servicerepclient1
<User>\Local Settings\Application Data\WINDOWS\SERVICES.EXE

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Logonrepclient1
<User>\Local Settings\Application Data\WINDOWS\CSRSS.EXE

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
System Monitoring
<User>\Local Settings\Application Data\WINDOWS\LSASS.EXE

HKCU\Software\Microsoft\Windows\CurrentVersion\Run
MSMSGS
<User>\Local Settings\Application Data\WINDOWS\WINLOGON.EXE

The following registry entries are set or modified, so that shell.exe is run when files with extensions of BAT, COM and PIF are opened/launched:

HKCR\lnkfile\shell\open\command
(default)
<System>\shell.exe" "%1" %*

HKCR\batfile\shell\open\command
(default)
<System>\shell.exe" "%1" %*

HKCR\comfile\shell\open\command
(default)
<System>\shell.exe" "%1" %*

HKCR\piffile\shell\open\command
(default)
<System>\shell.exe" "%1" %*

The following registry entries are set, disabling the Windows task manager (taskmgr) and the command prompt:

HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System
DisableCMD
1

HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System
DisableTaskMgr
1

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
DisableTaskMgr
1

Registry entries are set as follows:

HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
Hidden
0

HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
HideFileExt
1

HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
ShowSuperHidden
0

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