W32/Tilebot-DK is a worm and IRC backdoor Trojan for the Windows platform.
W32/Tilebot-DK spreads:
- to computers vulnerable to common exploits, including: LSASS (MS04-011), RPC-DCOM (MS04-012), WKS (MS03-049), PNP (MS05-039) and ASN.1 (MS04-007)
- to MSSQL servers protected by weak passwords
- to network shares protected by weak passwords
- via AOL Instant Messenger
W32/Tilebot-DK 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/Tilebot-DK includes functionality to access the internet and communicate with a remote server via HTTP.
When first run W32/Tilebot-DK copies itself to <Windows>\nvidGUIv.exe and creates the file <System>\remon.sys.
The file remon.sys is detected as Troj/RKFu-A.
The file nvidGUIv.exe is registered as a new system driver service named "nvidGUIv2", with a display name of "nvidGUIv" and a startup type of automatic, so that it is started automatically during system startup. Registry entries are created under:
HKLM\SYSTEM\CurrentControlSet\Services\nvidGUIv2\
The file remon.sys is registered as a new system driver service named "remon", with a display name of "remon". Registry entries are created under:
HKLM\SYSTEM\CurrentControlSet\Services\remon\
The following registry entries are set, disabling the registry editor (regedit) and the Windows task manager (taskmgr):
HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System
DisableTaskMgr
1
HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System
DisableRegistryTools
1
W32/Tilebot-DK 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\
Sophos's anti-virus products include Genotype™ detection technology, which can proactively protect against new threats without requiring an update. Sophos customers have been protected against W32/Tilebot-DK (detected as W32/Tilebot-Gen) since version 3.97.