AM.Accessiv.B

SUMMARY

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low
• Payload: This variant contains a payload. If the current month is March, the virus displays a message box with the title "AccessiV - Strain B" that has the following message: I am the AccessiV virus, Strain B Written by Jerk1N, of the DIFFUSION Virus Team AccessiV was/is the first ever Access Virus!!! The message box has buttons: Abort, Retry and Ignore. When any of the button is clicked, the virus attempts to drop a DOS file infector virus. However, it fails to do so.

Distribution

• Distribution Level: Low

TECHNICAL DETAILS

This is a modified variant of AM.Accessiv.A This virus works under Microsoft Access 97. The infection has:

• AutoExec macro
• Virus module

In Microsoft Access, macro is simply a set of actions to automate common tasks. One of the special macro is AutoExec, which MS Access executes automatically when a database is opened. When an infected database is opened, its viral AutoExec macro executes the Virus module. A module contains Visual Basic for Application code. The Virus module searches for MS Access database files (*.MDB) in the current directory, the parent of the current directory, and the root directory. It copies both AutoExec macro and Virus module to MDB file that it finds.

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.