VBS.Phram

SUMMARY

VBS.Phram is a script written in the Visual Basic Scripting language. However, the script has been put into an HTML file, and it spreads as a file named e-Gen.html.

When executed, the virus displays a message in the Web browser. VBS.Phram also contains a macro virus. Norton AntiVirus detects the macro virus as W97M.Phram.

Protection

• Virus Definitions (Intelligent Updater) February 23, 2001

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

Distribution

• Distribution Level: Low

TECHNICAL DETAILS

VBS.Phram is a Visual Basic Script that spreads using an HTML file. When executed, it displays a message in the Web browser window. At the bottom of the message are thank-you notes to a few people, and various viral IRC channels.

Next, VBS.Phram attempts to lower the security settings on the computer. However, the first time it is executed, if the security settings have not been lowered manually, a Microsoft ActiveX warning should appear. When it does, you have to option to not allow the script to run.

If this script is allowed to continue, it opens the C:Autoexec.bat file. At the very end of this file it adds the word pause.

If the operating system is a Windows 95 or 98, the computer will pause during startup and wait for you to press a key.

Next, the virus infects files in the C:My Documents folder by appending itself to files with the following extensions:

• .html
• .asp
• .htm
• .htt

(C:My Documents is the default location for this folder under Windows 95/98.)

Finally, this virus attempts to infect the Microsoft Word global template, Normal.dot, with a macro virus. Norton AntiVirus detects this macro virus as W97M.Phram.

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 worm:

1. Run LiveUpdate to make sure that you have the most recent virus definitions.
2. Start Norton AntiVirus (NAV), and run a full system scan, making sure that NAV is set to scan all files.
3. Delete, and if necessary, replace any files detected as VBS.Phram.
4. Repair any Microsoft Word documents detected as infected with W97M.Phram.