Threat Explorer

The Threat Explorer is a comprehensive resource consumers can turn to for daily, accurate, up-to-date information on the latest threats, risks and vulnerabilities.

VBS.Phram

VBS.Phram

Discovered:
23 February 2001
Updated:
13 February 2007

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.

Antivirus Protection Dates

  • Initial Rapid Release version 23 February 2001
  • Latest Rapid Release version 28 September 2010 revision 054
  • Initial Daily Certified version 23 February 2001
  • Latest Daily Certified version 28 September 2010 revision 036
  • Initial Weekly Certified release date pending
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

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":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • 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.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a 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.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. 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.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.

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.


Writeup By: Neal Hindocha