W32.Rahack

1. Creates the following files:
   
   • %System%\mscolsrv.exe
   • %System%\server.dll
   • %System%\svchsot.exe
   • %System%\syshid.exe
   • %UserProfile%\Start Menu\Programs\Startup\system.vbs
     
     Notes:
   • %System% is a variable that refers to the System folder. By default this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
   • %UserProfile% is a variable that refers to the current user's profile folder. By default, this is C:\Documents and Settings\<All Users> (Windows NT/2000/XP).
     
     
2. Adds the value:
   
   "sysser" = "%System%\[path to original file]"
   
   to the registry key:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   
   so that the worm is executed every time Windows starts.
   
   
3. Adds the value:
   
   "(Default)"= "syshid.exe "%1" %*""  
   
   to the registry key:
   
   HKEY_CLASSES_ROOT\exefile\shell\open\command
   
   
4. Creates the following registry entries:
   
   HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\MSCoolServ
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSCoolServ
   HKEY_LOCAL_MACHINE\SOFTWARE\RAdmin\v1.1
   HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0
   
   
5. Creates the following service:
   
   Service name: MSCoolServ
   
   
6. Searches for .htm and .html files and copies itself using the same name with an .exe extension.
   
   
7. Adds the values:
   
   "(Default)" = "sysser"  
   "(Default)" = "[path to executable]"
   
   to the registry key:
   
   HKEY_CLASSES_ROOT\CLSID\[random CLSID]
   
   
8. Inserts an objective tag into the .html files. The objective tag points to the CLSID that is created in the registry so that the worm is executed every time the .html files are opened.
   
   
9. Searches for IP addresses running Radmin, by connecting to IP addresses from [first octet].[second octet].0.1 to [first octet].[second octet].255.255 on TCP port 4899,
   
   Notes:
   • The first octet is randomly chosen from the following:
     12, 14, 24, 61, 62, 63, 64, 65, 66, 67, 68, 69, 80, 81, 82, 83, 84, 195, 199, 200, 201, 202, 203, 207, 209, 210, 211, 212, 213, 216, 217, 218, 219, 220, 221, 222
   • The second octet is randomly chosen from the following:
     0, 20, 40, 60, 80, 100, 120 ,140, 160, 18, 200, 220, 240
     
     Logs the details of any IP addresses running Radmin on TCP port 4899 in the file logX.txt in same folder as the worm.
     
     
10. Attempts to access the remote computers running Radmin, using the following passwords:
    
    • 123456789
    • 11111111
    • 12345678
    • password
    • qwertyui
    • 00000000
    • 12341234
      
      
11. Copies itself onto the remote computer as C:\wutemp\srvsxc.exe, and attempts to execute itself.

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.