HELP! Very weird goings on with computer/internet today

First I've had an unusual amount of trouble today getting on or staying on the internet. Okay that's happened on occassion when work is happening on trunk lines etc.

But then when I finally did get back on I get all these strange emails. One is warning me that my computer might be infected with Spyware and offers to scan my machine for me. Then I get FOUR emails from addresses I've never seen before with subject lines that say: "My details" or "That movie..." or "approved" or "thank you!" and each one comes with a message that says "please see the attached file for details". Of course I didn't open the file.
THEN I get a Mail Deliver Subsystem - Service Unavailable email that tells me some email I sent was undeliverable. But I don't recognize the address that I supposedly sent something to.

WHAT IS GOING ON???!!!! Have I been invaded by the cyber snatchers?
What should I do, or not do?

address. Just wait until the Asian spam people get it!

or a worm that is exploiting email addresses in your address book, possibly. Blaster is making the rounds now. Go to www.mcafee.com to read the blaster alert.

There's another worm going on - Welchia.Worm that sends an eternal ping to various sites. If you check Symantec (www.symantec.com) they have the fix.

There's also the new "Sobig" virus - that's what you go. Here's the details - http://securityresponse.symantec.com/avcenter/venc/data/w32.sobig.f@mm.html

From MSNBC...

http://www.msnbc.com/news/954470.asp?0cv=CB20

SoBig variant floods inboxes

<snip>

But even those who weren’t directly infected with the virus were struggling with it. When it replicates, the virus “spoofs” the sending e-mail address. That means the “From:” line is faked, selected from a list of e-mail addresses culled off the Internet. Users unlucky enough to be used in SoBig’s “From” line can get hundreds of SoBig-related complaints, including automated bounce messages saying the virus didn’t reach its recipient, or irate messages from recipients who think they’ve been sent a computer virus.

<snip>

Check the rest of the lounge, there are a bunch of posts on this.

It's the Sobig virus, Dover. See the link in LBN.

I thought my program was so old the viruses wouldn't get me.
Now I hope I understand the directions for getting rid of this virus....I'm terribly computer illiterate I'm afraid.