How Viruses Work

How Viruses Work
When a victim of a virus double clicks on an infected attachment, the virus will run.
The virus will modify the victim’s system so it will always be active when the system is turned on.
The virus will scan the victim’s address book in their e-mail client program such as Outlook or Outlook Express.
In the past, viruses would then mail themselves to addresses found in the victim’s address book. But today many viruses choose random recipients and senders from the victim’s address book. This means that although the e-mail is sent from the victim’s machine, the e-mail sender address is faked to appear as though someone else in the victim’s address book sent the message.
What to Do
Always run anti-virus software and be sure it gets updated at least twice per week.
If you get a virus in an e-mail attachment and you are sure it is a virus, delete the e-mail message.
If you get an attachment from someone you know, consider whether there is enough personal information in the e-mail which a virus program would not know. If you are not sure your acquaintance sent the e-mail call them and be sure before opening the attachment. Do not count on your anti-virus software being able to stop you from getting infected if you open the e-mail attachment. Remember, viruses are not recognized right away by your anti-virus software and you could get a new unrecognized virus before your virus definition updates are released.

If you get an e-mail saying a message you sent was undeliverable and you did not send the message, consider whether your system is behaving abnormally. You probably do not have a virus, but if you are not sure, use your anti-virus software to perform a system scan for viruses and remove any viruses found using the procedure in the section about “Removing Viruses”, then delete the e-mail.
If you get an e-mail saying a message you sent contained a virus, consider whether your system is behaving abnormally. You probably do not have a virus, but if you are not sure, use your anti-virus software to perform a system scan for viruses and remove any viruses found using the procedure in the section about “Removing Viruses”, then delete the e-mail.