Sophos

W32/Tilebot-U

Aliases
  • Backdoor.Win32.SdBot.aad
  • WORM_SDBOT.CFM
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 29 September 2005 06:45:16 (GMT)
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Action

More Information

W32/Tilebot-U is a worm and IRC backdoor Trojan for the Windows platform.

W32/Tilebot-U spreads to other network computers by exploiting common buffer
overflow vulnerabilities, including: LSASS (MS04-011), RPC-DCOM (MS04-012),
PNP (MS05-039) and ASN.1 (MS04-007) and by copying itself to network shares
protected by weak passwords.

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

When first run W32/Tilebot-U copies itself to <Windows>\svch0st.exe and creates
the file <System>\rdriv.sys.

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

The file svch0st.exe is registered as a new system driver service named
"BoolTern", with a display name of "BoolTern" and a startup type of automatic,
so that it is started automatically during system startup. Registry entries are
created under:

HKLM\SYSTEM\CurrentControlSet\Services\BoolTern\

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/Tilebot-U 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\

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

MS04-007
MS04-011
MS04-012
MS05-039

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