X97M.Avone.A  

X97M.Avone.A  
Discovered on: November 05, 2004 
Last Updated on: November 05, 2004 09:06:47 AM

Also Known As:  Macro.Excel97.Viki.a [Kaspersky]
 
Type:  Macro
Infection Length:  One VBA module
 
Systems Affected:  Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP

Technical Details:

When an infected workbook is opened, X97M.Avone.A performs the following actions:

Checks for the existence of the files 'AV1' and 'AV2' in the Excel startup folder. If these files do not exist, they are created.

AV1 is used as a counter of the number of times the virus has executed and the number of times it has infected other files.

AV2 contains the name of the infected workbook.

Saves the infected file into the Excel startup folder with a Cyrillic filename.

Copies itself into all workbooks that are opened.

Deletes all files in the same folder as the infected file. This only occurs after the virus has been executed at least 100 times and has infected at least 10 files.

Recommendations:

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.

Source: Symantec Security Response