While we were fighting blaster/nachi and others, we relied heavily on IDS's to generate
alerts for the worms, then we disabled their network access and called them.  Generic
viruses are not an ISP's problem, but a worm is something that affects the prviders
infrastructure, and is therefore a network operators business.
Privacy is not an issue in this case as there is a policy being monitored by a policy
monitoring tool, and enforced on a per-violation basis. It wasn't a fishing expedition
that could assess the users configuration or usage, it was monitoring our network.
There is no generalized way, without management access to the customers machine
(via SMS or citrix or something), to check that the machine is in compliance with a
network policy. An IDS can tell you if it violates policy, and you can act as your
security procedures dictate.
Jamie.Reid, CISSP, jamie.reid@mbs.gov.on.ca
Senior Security Specialist, Information Protection Centre
Corporate Security, MBS 
416 327 2324

>>> "Sean Donelan" sean@donelan.com> 10/05/03 04:49pm >>


So from an ISPs point of view, is there a way for the ISP to quickly
tell the customer if the particular computer is fixed without unduly
intruding on the privacy of the customer?  With home networks, there
may be multiple computers behind a NAT/router/firewall.  So a simple
network scan doesn't always work.