Sophos

W32/Tilebot-AO

Aliases
  • Backdoor.Win32.SdBot.aad
  • Sdbot.worm.gen.bd
  • W32.Spybot.Worm
Category
Type
What to do
Prevalence low high

Summary

 
How it spreads
  • Network shares
Affected operating systems Windows
Characteristics
  • Drops more malware
  • Installs itself in the registry
Protection available since 3 November 2005 21:34:45 (GMT)
Last updated 27 January 2006 03:13:48 (GMT)
Detected by All Sophos products
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Action

More Information

W32/Tilebot-AO is a worm with IRC backdoor functionality for the Windows platform.

W32/Tilebot-AO spreads to other network computers by exploiting common buffer overflow vulnerabilities, including: LSASS (MS04-011), RPC-DCOM (MS04-012), WKS (MS03-049) (CAN-2003-0812), PNP (MS05-039), IMAIL Server and ASN.1 (MS04-007).

The following patches for the operating system vulnerabilities exploited by W32/Tilebot-AO can be obtained from the Microsoft website:

MS04-011
MS04-012
MS03-049
MS05-039
MS04-007

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

When first run W32/Tilebot-AO copies itself to <Windows folder>\clmss.exe and creates the file <Windows system folder>\hpdriver.sys.

The file hpdriver.sys is detected as Troj/Rootkit-AA.

The file clmss.exe is registered as a new system driver service named "Content List Management Sub System", with a display name of "clmss" and a startup type of automatic, so that it is started automatically during system startup. Registry entries are created under:

HKLM\SYSTEM\CurrentControlSet\Services\Content List Management Sub System\

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

HKLM\SYSTEM\CurrentControlSet\Services\hpdriver\

W32/Tilebot-AO 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\

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