++Virus Guardian++: 04/19/06

Brontok Virus Analysis

Name :
-W32/Brontok-J
Type :
-Worm
How it spreads :
-Email messages
Affected operating:
-systemsWindows
Side effects :
-Sends itself to email addresses found on the infected computer
-Modifies data on the computer
-Installs itself in the Registry
Aliases :
-W32.Rontokbro@mm
-Email-Worm.Win32.Brontok.c

Virus Description

W32/Brontok-J is an email worm for the Windows platform.

W32/Brontok-J attempts to send itself to email addresses harvested from the computer. It will also attempt to modify various Windows Explorer settings.

W32/Brontok-J will restart the computer if it finds a window title containing certain strings such as ".EXE".

Advanced

This section is for technical experts who want to know more.

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

W32/Brontok-J attempts to send itself to email addresses harvested from the computer. It will also attempt to modify various Windows Explorer settings.

W32/Brontok-J will restart the computer if it finds a window title containing certain strings such as ".EXE".

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

<User>\Local Settings\Application Data\br4941on.exe
<User>\Local Settings\Application Data\csrss.exe
<User>\Local Settings\Application Data\inetinfo.exe
<User>\Local Settings\Application Data\lsass.exe
<User>\Local Settings\Application Data\services.exe
<User>\Local Settings\Application Data\smss.exe
<User>\Local Settings\Application Data\svchost.exe
<User>\Start Menu\Startup\Empty.pif
<Windows>\KesenjanganSosial.exe
<Windows>\ShellNew\RakyatKelaparan.exe
<System>\cmd-brontok.exe

W32/Brontok-J will drop various files in My Docuement\My Pictures folder with message from the virus writer.

The following registry entries are created to run br4941on.exe and RakyatKelaparan.exe on startup:

HKCU\Software\Microsoft\Windows\CurrentVersion\Run
Tok-Cirrhatus-1959
<User>\Local Settings\Application Data\br4941on.exe

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Bron-Spizaetus
<Windows>\ShellNew\RakyatKelaparan.exe

The following registry entry is changed to run KesenjanganSosial.exe on startup:

HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
Shell
Explorer.exe "<Windows>\KesenjanganSosial.exe"

(the default value for this registry entry is "Explorer.exe" which causes the Microsoft file <Windows>\Explorer.exe to be run on startup).

The following registry entry is set, disabling the registry editor (regedit):

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

Registry entries are set as follows:

HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
NoFolderOptions
1

HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System
DisableCMD
0

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