Get a strange email from your mom or best friend — or even from us — with an attachment? Unless you know exactly what it is and have been expecting it — don’t open it!
And your caution should extend even farther than just attachments. In fact, the most annoying and widespread virus out there is actually a worm called Klez — and it doesn’t even appear to carry an attachment. It arrives in your inbox bearing any one of over 50 subject lines, such as introduction on ADSL, Questionnaire, A WinXP patch, Japanese girl VS playboy, some questions and A special humour game. One particularly nasty thing about this worm: It fakes “from” addresses. That means, while it may appear that dear old Aunt Mabel sent it to you, it probably didn’t actually come from her. As Symantec says, the worm randomly selects an address that it finds on an infected computer (from address books and from web sites), and ttis is how this worm spreads itself. So, in addition to religiously updating your virus protection files at least weekly and not opening strange attachments, the most current advice is: Don’t even open or preview a message if it comes with any of the above subject lines (or variations thereof).
According to McAfee, simply opening or previewing the message in a vulnerable mail client can result in an infection of your machine.