[brianlb]

I have been receiving numerous e-mail notifications that messages I am supposed to have sent are undeliverable: almost all of these have been addressed to ntlworld.com recipients. I have not myself sent any of them. Several have had attachments which have been deleted as infected by Norton AV. Most have been "returned" as undeliverable because the recipient's mailbox is full or its quota has been exceeded -- which suggests that they have been receiving hundreds of virus-initiated messages, some or all of them infected. I receive around 200 spams every day addressed to my ntlworld.com address and around 10 to 15 of these contain viruses (mostly netsky) detected and quarantined by Norton AV. I delete them from my Inbox and from the quarantine folder in Norton.

I have been assuming that as Norton has eliminated all infected files that it has found, the messages supposedly sent from my PC have actually been sent from the PC of someone else who has my ntlworld.com address in his or her address book. But now NTL appears to be saying that the messages have actually come from my PC. A web page has appeared in my browser which appears to come from NTLHome (my ISP is ntlworld.com) containing the following message:
"Virus Infection Alert
You have been redirected to this page because we can see from messages coming from your internet connection that your computer has been infected with the NetSky virus.
This virus will not cause any serious damage, and you may not even know that your PC is infected. However because of the way the virus sends out masses of instructions onto the internet, it is slowing down your connection speed as well as causing congestion on our network, affecting the connection speeds of all our customers, and you must disinfect your computer before we can allow you to connect to the ntl network again.
Your computer can be disinfected and ready to browse the internet again in a few minutes by following this simple process. Please click on the link below to continue."

The NTL web page invited me to download and run a McAfee virus checker (stinger.exe) which I did. Before deciding whether to run stinger.exe, I did a virus scan with Norton AV of my whole hard disk. It found no infected files. I then ran stinger.exe which also didn't find any infected files. I was then able to access other websites.

My Windows XP firewall is activated, I use a dialup connection, and my Windows updates are up to date.

This seems to confirm that the infected messages which pretend to be coming from my PC are in fact coming from someone else's PC that has my e-mail address in its address book. If so, running stinger.exe on my own PC won't stop these messages from going out and I shall soon get blocked again by NTL and forced to run stinger.exe again (it took about 45 minutes to scan my HD). How do I convince NTL that my system is not infected in spite of all these messages going out in my name?

Urgent advice would be welcome!

Brian