When an infected document is opened, the virus creates the C:\Avmshare.dll file and copies its viral macro to the file. Using the created file, the virus infects the Normal.dot template. Thereafter, all documents that use the Normal.dot template will be infected when they are opened.
This virus also disables Microsoft Word macro virus protection.
After the infection occurs, the virus attempts to delete macros that are not named either of the following:
Antivirii
ThisDocument
This attempt is not successful, however, due to bugs in the virus code.
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.
To remove this virus:
Run LiveUpdate to make sure that you have the most recent virus definitions.
Start Norton AntiVirus (NAV), and then run a full system scan, making sure that NAV is set to scan all files.
If any files are detected as infected by W97M.Surround.C, then click Repair.
(Optional) Use Windows Explorer to locate and delete the following file:
