W32.HLLP.Shodi.B

1. Extracts the original host file to a file with a .ogr extension, and then executes it.
   
   For example, if Notepad.exe is infected, the virus will extract the original Notepad program to Notepad.ogr, and then will run it.
   
   
2. Attempts to install a backdoor to an infected system by creating the following files:
   
   • %System%\oobb.exe: An installer detected as Backdoor.Trojan.
   • %System%\Cheatle.exe: A VB application detected as Backdoor.Trojan.
   • %System%\GigaByte.exe: A remote administration tool detected as Remacc.Radmin.
   • %System%\AdmDll.dll: A .dll component of Remacc.Radmin.
   • %Windir%\r_server.exe: Another copy of GigaByte.exe.
   • %Windir%\start.exe: Another copy of Cheatle.exe.
     
     

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     Notes:
   • Some variants of this virus create %System%\oobb.exe as a zero-byte file. In this case, the other files will not be present.
   • %Windir% is a variable. The virus locates the Windows installation folder (by default, this is C:\Windows or C:\Winnt) and copies itself to that location.
   • %System% is a variable. The virus locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).

     ---

     
     If these files are successfully dropped, they will add the following entries
     
     "Cheatle"="%System%\GigaByte.exe /port:6351 /pass:hellomine"
     "GigaByte"="%System%\Cheatle.exe"
     
     to the registry key:
     
     HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
     
     so that the backdoor runs when Windows starts.
     
     The backdoor is configured to listen on TCP ports 6351 and 6352.
     
     
3. Searches for the files that have the .exe extensions on all the hard drives, starting with drive C. The worm searches all the folders on the hard drive, except those with the following names:
   
   • Windows
   • System
   • System32
     
     It does not infect the files that have the following names:
     
   • IEXPLORE.EXE
   • ccApp.exe
   • ccRegVfy.exe
     
     
4. Prepends itself to some of the files that it finds.
   
   The virus infects Portable Executable (PE) files that have a resource directory. Such files often contain a custom icon in the .rsrc section of the file. This icon is displayed instead of the default Windows icon.
   
   When the virus infects such a file, it modifies its own icon to resemble the icon of the host file.
   
   
5. Makes a temporary copy of itself as %System%\ShohdiWithPrograms.ams.
   
   
6. If the worm is executed on May 5, 2005, the virus will display a message box containing the text:
   
   Important !!!
   Please read this
   The Next is in Arabic
   
   followed by Arabic text.

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.