W2K.Team

SUMMARY

W2k.Team is a simple virus that infects .exe files that are in the same folder as the virus when the virus is executed. The virus runs only on Windows 2000 and Windows XP systems.

Behavior

Symptoms

Transmission

Protection

• Virus Definitions (LiveUpdate™ Weekly) May 29, 2002
• Virus Definitions (Intelligent Updater) May 29, 2002

TECHNICAL DETAILS

When W2k.Team is run, it copies the original file to a separate NTFS stream with the added name ":ccc". For example, if the original file name was Notepad.exe, the virus would to the following:

1. It first copies Notepad.exe to the file "2002"
2. Next, it copies the virus to Notepad.exe
3. Finally, it copies the file "2002" (the original Notepad.exe) to the NTFS stream Notepad.exe:ccc

Upon executing an infected file, the virus will execute the original file by creating a process containing the code in the NTFS stream, for example, in Notepad.exe:ccc.

Recommendations

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

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended 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 (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• 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.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. 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.

REMOVAL

To remove this virus, copy the NTFS stream [Infected Filename]:ccc to [Infected Filename] and then delete the NTFS stream,
[Infected Filename]:ccc.