The worm, called VBS.Hard.A@mm, shows up in users' in-boxes disguised as a virus alert from antivirus firm Symantec, the company said in a virus alert. With a subject line reading "FW: Symantec Anti-Virus Warning" and an attachment bearing the name "www.symantec.com.vbs," the relatively innocuous worm, like many other recent worms, is written in Microsoft's Visual Basic script (VBS) and propagates through the company's Outlook Express e-mail client. The e-mail carrying the worm is sent by "F. Jones," who the e-mail identifies as a Symantec senior developer.
When a user double clicks on the attachment, thus launching the file, a number of things happen. First, the default Web page that the PC's Web browser is set to visit upon launch is changed to a fake Symantec virus information page. The worm then sends itself to everyone in the infected PC's Outlook Express address book. The worm also makes some changes to the computer's registry files. Lastly, it creates a dialog box which will appear on 24 November and reads, "Don't look surprised! It is only a warning about your stupidity Take care!"
Though the worm is low-risk and does not cause serious damage, it is likely to spread quickly, Symantec said.
To remove the worm, users should be sure to update their virus definitions, run up-to-date virus scans and delete any files reported as being related to the worm. Changing the default Web page in the browser must be done manually. Instructions on how to delete the changes made to the computer's registry are available on Symantec's Web site, on the page detailing the virus.
The VBS.Hard.A@mm worm is only the latest in a flurry of e-mail worms that have spread in the last few months. Thanks to alerts and the repeated chidings of antivirus companies, users have become more informed and sceptical, limiting the spread of viruses, according to virus researchers. However, as users are becoming more informed, so too are virus and worm writers changing their tactics, according to virus experts.
VBS.Hard.A@mm and other recent worms employ a technique called social engineering to enable their spread. Social engineering is a technique in which, in this case, a virus or worm writer, will attempt to trick a user into helping spread their work by disguising it as something fun or useful, like an antivirus alert message. The recent Anna Kournikova and Naked Wife viruses both used these techniques.
As always, users are cautioned to be sure they have the most up to date antivirus protection and not to open unexpected e-mail attachments. Even if they are from an anti-virus company.