Summary

Summary
Action
More Information
| How it spreads |
|
|---|---|
| Affected operating systems | Windows |
| Characteristics |
|
| Protection available since | 24 December 2004 16:41:53 (GMT) |
| Last updated | 26 January 2005 10:10:12 (GMT) |
| Detected by | All Sophos products |
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Action

Summary
Action
More Information
Please follow the instructions for removing worms.
Change any data that may have become compromised.
You will also need to edit the following registry entries, if they are present. Please read the warning about editing the registry.
At the taskbar, click Start|Run. Type 'Regedit' and press Return. The registry editor opens.
Before you edit the registry, you should make a backup. On the 'Registry' menu, click 'Export Registry File'. In the 'Export range' panel, click 'All', then save your registry as Backup.
Locate the HKEY_LOCAL_MACHINE entries:
HKLM\Software\Microsoft\Windows\CurrentVersion\Run
HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices
and remove any reference to any file you deleted.
Each user has a registry area named HKEY_USERS\[code number indicating user]\. For each user locate the entry:
HKU\[code number]\Software\Microsoft\Windows\
CurrentVersion\Run\
and remove any reference to any file you deleted.
Close the registry editor.
Check the following items
- To renable DCOM you can edit the registry, but it's better to use Dcomcnfg.exe. See Microsoft article 825750 for details.
- The HKLM\SYSTEM\CurrentControlSet\Control\Lsa\restrictanonymous = "1" setting does not allow enumeration of SAM accounts and names. The default is "0". It can be changed in Local Security Policy. See Microsoft article 246261 for details.
- Check your administrator passwords and review network security.
More Information
W32/Rbot-SI is an IRC backdoor Trojan and network worm.
W32/Rbot-SI may spread to remote network shares protected by weak passwords and computers vulnerable to common exploits. The worm also opens up a backdoor, allowing unauthorised remote access to infected computers via the IRC network, while running in the background as a service process.
W32/Rbot-SI can receive commands from a remote intruder which include instructions to delete network shares, log keypresses, participate in DDoS attacks, scan other computers for vulnerabilities, steal passwords, steal registration keys for computer games, create administrator accounts and start a proxy server.
W32/Rbot-SI copies itself to the Windows system folder and creates the following registry entries to run automatically on log-on:
HKLM\Software\Microsoft\Windows\CurrentVersion\Run
Windows Media Player
msa.exe
HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices
Windows Media Player
msa.exe
HKCU\Software\Microsoft\Windows\CurrentVersion\Run
Windows Media Player
msa.exe
W32/Rbot-SI also attempts to alter the following registry entries if they were not already set:
HKLM\SOFTWARE\Microsoft\Ole
EnableDCOM
"N"
HKLM\SYSTEM\CurrentControlSet\Control\Lsa
restrictanonymous
1
