Summary

Summary
Action
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| How it spreads |
|
|---|---|
| Affected operating systems | Windows |
| Characteristics |
|
| Protection available since | 13 February 2007 01:51:08 (GMT) |
| Detected by | All Sophos products |
- Endpoint Security and Control 9.0
- Small business solutions 4.0
Action

Summary
Action
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Please follow the instructions for removing worms.
More Information
W32/Tilebot-IU is a worm for the Windows platform.
W32/Tilebot-IU spreads to other network computers by exploiting common buffer overflow vulnerabilities, including RealVNC (CVE-2006-2369) and by copying itself to network shares protected by weak passwords.
W32/Tilebot-IU 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.
When first run W32/Tilebot-IU copies itself to <Windows>\lsass.exe.
The file lsass.exe is registered as a new system driver service named "LSA Shell Export-Version", with a display name of "LSA Shell Export-Version" and a startup type of automatic, so that it is started automatically during system startup. Registry entries are created under:
HKLM\SYSTEM\CurrentControlSet\Services\LSA Shell Export-Version
W32/Tilebot-IU may modify the following files:
<System>\ftp.exe
<System>\sfc_os.dll
<System>\tftp.exe
The file sfc_os.dll is modified in an attempt to disable the System File Checker. The files ftp.exe and tftp.exe are replaced by non-functional versions.
Registry entries are set as follows:
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
SFCScan
0
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
SFCDisable
ffffff9d
