W32/Kassbot-L

Please follow the instructions for removing worms.

W32/Kassbot-L is a worm for the Windows platform.

W32/Kassbot-L runs continuously in the background, providing a backdoor server which allows a remote intruder to gain access and control over the computer via IRC channels.

W32/Kassbot-L spreads via network shares and by exploiting the following software vulnerabilities:

LSASS ( MS04-011 )
RPC-DCOM (MS04-012)
PNP (MS05-039)
ASN.1 (MS04-007)

W32/Kassbot-L includes functionality to access the internet and communicate with a remote server via HTTP.

When first run W32/Kassbot-L copies itself to <Windows>\msnmgr.exe and creates the file <System>\rdriv.sys.

The file rdriv.sys is detected as Troj/Rootkit-W.

The file msnmgr.exe is registered as a new system driver service named "Manager", with a display name of "Windows XP Manager" and a startup type of automatic, so that it is started automatically during system startup. Registry entries are created under:

HKLM\SYSTEM\CurrentControlSet\Services\Manager\

The file rdriv.sys is registered as a new system driver service named "rdriv", with a display name of "rdriv". Registry entries are created under:

HKLM\SYSTEM\CurrentControlSet\Services\rdriv\

W32/Kassbot-L sets the following registry entries, disabling the automatic startup of other software:

HKLM\SYSTEM\CurrentControlSet\Services\Messenger
Start
4

HKLM\SYSTEM\CurrentControlSet\Services\RemoteRegistry
Start
4

HKLM\SYSTEM\CurrentControlSet\Services\TlntSvr
Start
4

Registry entries are set as follows:

HKLM\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate
DoNotAllowXPSP2
1

HKLM\SOFTWARE\Microsoft\Ole
EnableDCOM
N

HKLM\SYSTEM\CurrentControlSet\Control\Lsa
restrictanonymous
1

Registry entries are created under:

HKLM\SOFTWARE\Microsoft\Security Center\
HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\DomainProfile\
HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\StandardProfile\