W32.Orpheus.A

1. Checks the following registry value:
   
   HKEY_LOCAL_MACHINE\Software\Cerberus\1.1\dontInstall
   
   If the value is set, the worm will exit without performing any further actions.
   
   
2. Copies itself to %System%\hotplug.exe.
   
   Note: %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).
   
   
3. Creates the service:
   
   "Hotplug Devices Manager"
   
   associating it with:
   
   %System%\hotplug.exe
   
   so that it is executed on boot time with SYSTEM privileges.
   
   Note: This service will have the following description: Enables automated driver loading for hotpluggable devices, including USB, FireWire and Hotplug PCI systems. If this service is stopped, hotplug devices will no longer function. If this service is disabled, any services that explicitly depend on it will fail to start.
   
   
4. Adds the value:
   
   "DependOnService" = "HotPlug"
   
   to the registry key:
   
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\PlugPlay
   
   so that the Microsoft Plug n Play service depends on the worms newly installed malicious service for startup.
   
   
5. Injects ntadint.dll in any running process with a name containing the string "lsass." This dll contains the backdoor and network-spreading features of the worm.
   
   
6. When the dll is executed, it patches the following APIs to try to hide its presence on the system.
   
   • CreateProcessA
   • CreateProcessW
   • LoadLibraryExW
   • FreeLibrary
   • CreateProcessAsUserA
   • CreateProcessAsUserW
   • FindFirstFileExW
   • FindNextFileW
   • RegCloseKey
   • RegEnumKeyW
   • RegEnumKeyA
   • RegEnumKeyExW
   • RegEnumKeyExA
   • RegEnumValueW
   • RegEnumValueA
   • RegQueryMultipleValuesA
   • RegQueryMultipleValuesW
   • EnumServicesStatusA
   • EnumServicesStatusW
   • DispatchMessageA
   • DispatchMessageW
   • GetMessageA
   • GetMessageW
   • LogonUserW
   • LogonUserA
   • RegOpenKeyExW
   • RegQueryValueExW
   • WlxLoggedOutSAS
     
     The dll will attempt to inject itself into any process making a call to these APIs.
     
     
7. May log user keystrokes to c:\irdos.sys.
   
   
8. Opens a backdoor on the system by creating the following named pipe:
   
   cb_win_nt_proc_rpc_[current process id]
   
   
9. Once connected, the remote user can perform a number of actions including:
   
   
   • View system details.
   • Retrieve keystroke log files.
   • Clear keystroke log files.
   • Change user passwords.
   • Create a user.
   • Delete users.
   • Execute a command.
   • Perform a DoS on a specified remote host.
   • Open shares.
     
     
10. Uses the output of the command:
    
    net view /domain
    
    to iterate through all the domains known to the infected host, attempting to connect to all the listed hosts.
    
    
11. If a successful connection is made, it will attempts to copy the following files:
    
    • %System%\ntadint.dll
    • %System%\hotplug.exe
    • d:\hotplug.exe
    • d:\ntadint.dll
      
      to the remote host.
      
      
12. Creates the following services on the remote computer:
    
    • Hotplug Devices Manager
    • Microsoft Windows Hotplug Service
      
      so that each of these files will be executed on system startup.

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.