"Recently the company's e-mail (which is posted on the company's website) has been absolutely flooded with spam....about 1200 a day. Normally we get about a dozen a day which slip through the spam filter and there are about 50 to 80 in the spam folder."
What email client are you using. It sounds like more filtering needs to be done.
Is there anything about the spam that is similar? The isps they are sent from? Commonality in the messages?
"I know there are viruses and spiders etc that can cause e-mails to become flooded with spam. Virus scans have been used on all of the computers. Norton's and Panda on the computers downstairs and AntiVir on mine. I also use SpyBot on mine. Nothing has been found."
Try the following on-line scan:
Windows One Care Free Scan
Go to Windows Live Onecare Free Scan (using Windows Explorer only)
It will say "Get a free PC safety scan"http://safety.live.com/site/en-us/default.htm
Make sure you click "Full Service Scan"
in the middle of the page and not the "Try It Now Free" on the right side.
Allow it to download the Active X components.
Choose "Complete Scan" in the window that opens
Do not click on anything else that offers you a free trial or to sign up if you live in the US.
Allow it to scan - it may take quite, maybe two hours or so depending on how big your hard drive is and how fragmented your registry and drive are.
Also try the following:
Trojan scans –
Windows Security Trojanscanhttp://windowsecurity.com/trojanscan
See instructions for it here:http://www.windowsecurity.com/trojanscan/trojanscan.asp
Parasite scan from Aumha:http://www.aumha.org/a/noads.php
"1) What can cause this sudden surge of spam?"
Mostly miscreants who profit from it.
"2) If I deny access of a virus or trojan to my computer via AntiVir can it "bounce" off mine to the other computers?"
"Bounce off"? No- but they are using the same ISP you are and can become infected the same way.
"3) Can the other computers pick up viruses from my computer even though they aren't networked? The only thing they share is the internet connection."
No- If they have no access to anything on your computer they cannot become infected by it except if your computer becomes infected and becomes a Zombie, or because of malware infection sends viruses and trojans to everyone in your address book (and/or possibly data you may have on your computer that can be ordered to be sent to the miscreants who infected you).
"4) This one is a different topic but I'm curious. Can the boss use his computer to see what sites I have been visiting? I am not connected directly to his computer. Just connected to his Livebox."
There are programs that can be installed on your computer that would enable someone to see everything you do on the computer you use.
There are also programs that can determine exactly what the internet connection is doing and which computer is doing it.
Is your computer really yours, or is it a computer owned by the business?
If it is owned by you it is less likely that a keylogger has been installed on it but if it's theirs, who knows?