The Melissa Virus was one of the first widespread viruses, which spread by infecting Microsoft Word files.
When the Word files were opened, the virus code would run and infect the Normal.DOT template file used by the Microsoft word program.
Now any Word document saved contained the Melissa virus.
Melissa used the autorun macros in a Word document and ran a VB script when an infected Word document was first opened.
Microsoft now has a feature called Macro Virus Protection that can stop macros from running and this protection should not be disabled.
If the virus has attached itself to an application, the code in the virus is run every time the application runs. The virus code will have the same privileges as the host application.
1) The Melissa virus is an excellent example of the need for effective email scanning
2) When a user opens the document, the virus infecs the user's machines.
3) The virus instructs the email client application to send an email message, complete with the infected attachment, to the first fifty contacts in the client's email address book.
4) The inundation of email can quickly overburden Microsoft Exchange servers.
Non- Microsoft SMTP/POP3 servers can be overburdened if too many system machines are sent too many emails.