Well, chalk up even more points for the Mac. It turns out I have been bombarded by the MyDoom virus–and I wasn’t even aware of it! Having a Mac and all can be an advantage, as such pernicious worms and trojan horses simply bounce off, leaving my computer completely unaffected.

However, if you happen to get your email on a Windows PC (my condolences), then you should be aware that the MyDoom virus has probably arrived on your computer several times since late January. I myself have received a dozen or more variations. Here’s how to tell:

First, the email comes with an attachment. That should be your first big warning–NEVER open an email attachment until you are 200% certain of what it is by means of foolproof authentication (e.g., calling up the sender and asking them exactly what they sent and why). MyDoom creates variations of the attachment’s document name, a trick which nonetheless raised my suspicions when I found myself getting short emails with attachments named “readme,” “document,” “test,” “text,” “data,” and a few other names–but they are all short, generic–and came in ZIP file format.

Most of them came with a simple one-line message, reading, “The message cannot be represented in 7-bit ASCII encoding/Unicode characters and has been sent as a binary attachment.” Other variations include faked “failed delivery,” “undelivered mail” or “returned mail” messages.

It’s the variations that are tricky–they make the emails look slightly different. Some variations come with a scrambled-foreign-language message with the attachment, a trick that would have zapped a friend of mine had she not had antivirus software running, lucky her.

So what will happen if you’re infected? According to McAfee’s virus library, two things. First, MyDoom will steal your email addresses from you address book and generate some new email addresses, then send the worm to them; in addition, it will open ports (data access points) on your computer, making it so that hackers could take control of your machine. This page also provides a detailed description.

So you get that kind of email, steer clear–and always steer clear of attachments unless you’re doubly sure.

Update: and they keep on coming. Not 5 minutes after I posted this, another MyDoom email arrived, making for a total of fifteen since January 26th.