Comcast to notify subscribers with infected PCs
Bot alert program goes nationwide
Comcast, the biggest US residential internet service provider, has begun offering all its subscribers a service that warns them when their PCs are infected with botnet software that steals banking passwords and carries out other nefarious deeds.
Over the next few months, the Philadelphia-based internet provider will roll out the service to all 16 million of its subscribers. Customers whose PCs appear to be infected will receive an email notifying them that they should visit a security page that has links to Microsoft security updates, free anti-virus software, and other resources. Infected users will also find a semi-transparent banner that's superimposed over their web browser that warns “Comcast has detected that there may be a virus on your computer(s).”
Comcast's Constant Guard  is an expansion of a pilot program rolled out last year in Colorado. Competing US providers including Cox Communications  and Qwest have offered similar services for years now. Microsoft executives have also floated the idea of putting infected PCs in rubber rooms .
Comcast's plan is admirable, but it's sure to confuse some subscribers. Aside from the difficulty of explaining to Aunt Mildred what a botnet is, Comcast's service flags only the subscriber IP address that is infected. That means homes that have Wi-Fi networks with a dozen or more PCs connected won't have an easy way to pinpoint the one that's compromised. ®