However, some viruses are destructive and may erase or damage your files and should be removed from your computer as soon as possible. One source of infected documents is attachments to electronic mail messages, another is in files downloaded from the internet. The symptoms of this virus are that a message box containing the number 1 appears on the screen. Thereafter, every newly created document is infected with the virus, and every attempt to save the file brings up the Save As dialogue. The first macro virus affecting Excel spreadsheets was the Laroux virus.
Infected spreadsheets contain a hidden sheet named laroux .
Another common Word Macro Virus is the CAP virus. It also affects the way documents are saved, saving documents as doc1, doc2 etc., without the chance to give a proper name. Note than Word and Excel virus names are listed with a WM or XM prefix. There are a number of products which can be used for detecting and removing software viruses. At Heriot-Watt, we have a site licence for Dr Solomon s Total Virus Defense.