W32.Looked.I

1. Creates the following files:
   
   
   • %Windir%\rundl132.exe (A copy of W32.Looked.I)
   • %CurrentFolder%\vDll.dll (A copy of Download.Trojan)
     
     Notes:
   • %CurrentFolder% is a variable that refers to the folder where the risk was originally executed.
   • %Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows or C:\Winnt.
     
     
2. Checks for the presence of the following registry entry, and exits if it finds it:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Soft\DownloadWWW\"auto" = "1"
   
   Note: If the above registry entry does not exist, the worm will create it as an infection marker.
   
   
3. Adds the value:
   
   "load" = "%Windir%\rundl132.exe"
   
   to the registry subkey:
   
   HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\WIndows
   
   to ensure it gets automatically executed at startup.
   
   
4. Attempts to stop the following service:
   
   Kingsoft AntiVirus Service
   
   
5. Injects its DLL component, vDll.dll, into either IEXPLORE.EXE or EXPLORER.EXE.
   
   
6. Tries to download and execute the following files from[http://]www.17dk.com/g[REMOVED]:
   
   
   • zt.txt
   • zt.exe
   • wow.txt
   • wow.exe
   • mx.txt
   • mx.exe
     
     Note: The downloaded files are copies of Infostealer.Lineage.
     
     
7. Searches for .exe files to infect in all the drives from C to Y.
   
   
8. Prepends itself to any .exe files that it locates on the computer.
   
   The worm will not infect .exe files in folders with the following names:
   
   
   • system
   • system32
   • windows
   • Documents and Settings
   • System Volume Information
   • Recycled
   • winnt
   • Program Files
   • Windows NT
   • WindowsUpdate
   • Windows Media Player
   • Outlook Express
   • Internet Explorer
   • ComPlus Applications
   • NetMeeting
   • Common Files
   • Messenger
   • Microsoft Office
   • InstallShield Installation Information
   • MSN
   • Microsoft Frontpage
   • Movie Maker
   • MSN Gamin Zone
     
     
9. Sends ICMP packets containing the string "Hello,World" to the following IP addresses:
   
   
   • 192.168.0.30
   • 192.168.8.1
     
     
10. Sends ICMP packets to IP addresses in the same range as the IP address of the compromised computer.
    
    
11. Attempts to open shared folders with the following names on any computer that responds to the ICMP packets:
    
    
    • \\ipc$
    • \\admin$
      
      The shared folder will have the user name "administrator" and a blank password.
      
      
12. Copies itself to any shared folder that it succeeds in opening.
    
    
13. Enumerates all the computers and shared folders in the local network. The worm uses a blank user name and a blank password to open the shared folders.
    
    
14. Searches for and infects .exe files in the shared folders.

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
• Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
• Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
• Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
• If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
• If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
• For further information on the terms used in this document, please refer to the Security Response glossary.