- 22 January 2002
- 13 February 2007
VBS.Funcess is a Visual Basic Script (VBS) worm that attempts to send itself by mIRC and Pirch IRC clients.
When it is executed, VBS.Funcess does the following:
It determines whether it has already infected your computer by checking for the existence of the following registry key:
If the key does not exist, the worm copies itself to the \Windows\System folder as a random name with the extension .vbe.
It then adds the \Open subkey to the following key:
so that the worm runs when you start Windows.
It then copies itself to the \Windows folder as Opel.vbs.
Next, it searches all drives for folders that contain the files Mirc.ini or Pirch98.ini. If it finds these files, it creates the files Script.ini or Events.ini, respectively. These .ini files contain commands to send itself using the IRC client.
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.
To remove this worm, delete files that are detected as VBS.Funcess or IRC.Worm.gen, and remove the key that the worm added to the registry.
To remove the worm:
- Run LiveUpdate to make sure that you have the most recent virus definitions.
- Start Norton AntiVirus (NAV), and make sure that NAV is configured to scan all files. For instructions on how to do this, read the document How to configure Norton AntiVirus to scan all files.
- Run a full system scan.
- Delete all files that are detected as VBS.Funcess or IRC.Worm.gen.
To edit the registry:
CAUTION : We strongly recommend that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to back up the Windows registry for instructions.
- Click Start, and click Run. The Run dialog box appears.
- Type regedit and then click OK. The Registry Editor opens.
- Delete the following key:
NOTE: Make sure that you navigate all the way to the \Open subkey.
- Click Registry, and click Exit.