Those who write virus programs have really gotten creative of late. One feature that some genius came up with was to have the virus snoop your address book, pick a name at random, and then send itself out to others under that NEW name it chose. Just because an email says it came from "John" doesn't mean anything anymore. If "Mary" is in "Sam's" address book, and so is "John", the virus can hit Sam, find John, take his name, and then go out to Mary. Even though "Sam's" PC sent it, it claims to be from John. If there are 20 people in your address book, and you get a virus like this, it can go out to all 20 people under 20 different names - all coming from YOU in reality.
And since the Archive server is in a lot of address books, as
[email protected], it's a prime spoof name to be used.
There are even ones out there that can fake their own headers now, as Andrew posted. It may have come from someone in outer Mongolia for all you know...but if it latched onto the information from someone in Michigan, it can spoof that stuff too.
One would think that someone so smart and creative would turn their talents into something fun that might be enjoyable and make them money, but alas, this is not so.
What this comes down to is the need to keep your PC protected by anti-virus software that is up to date at all times, and not to open attachments until they've been scanned. Most ISP's are now doing that before you even get the message, and then it has to go through your scanner as well.
About the only files you can be sure of that are virus free are image files, which cannot carry a virus in their code. The code in image files is what makes the picture, and inserting viral code into it scrambles the picture because the very nature of the file, such as .jpg, reads this code as picture alterations. You can learn more about image file extensions by doing a web search. There's a lot of them out there.