UK ISP TalkTalk, which has around 5 million customers, will commence a free security service which records every URL that its customers request in coming weeks.
If it discovered that a page was hosting a virus, the ISP would stop the page from rendering at the customer's end and would instead present a warning page.
"We now expect to be able to commence trials for a limited number of customers who have agreed to test our anti-malware system in the next few weeks," TalkTalk's managing director Clive Dorsman said Wednesday.
The ISP said it was acutely aware of potential privacy concerns, reassuring customers that their privacy would be maintained and that it had notified the Information Commissioners Office of its program.
"The system simply records the destination website URLs; it does not record who sends the request or other personal data with the URL," said Dorsman.
The opt-in service also included a parental control mechanism and would also provide customers with an override mechanism if they insist on viewing the page.
TalkTalk's anti-malware service stood in contrast rival ISP Virgin Media's service launched in August.
Virgin's service qs underpinned by The Shadowserver Foundation, which alerted ISPs to home connections that showed signs of being infected.
Virgin sent its customers a letter if they appeared on the list, providing advice on how to access free remediation services.
TalkTalk said it was pursuing a web-threat security program because security experts estimated that 70 percent of infections came via compromised web pages.
A recent study suggested ISPs could play a crucial role in the war on cybercriminals. The study, which analysed 190 billion spam messages, found that half the world's zombie computers were connected to the internet by just 50 ISPs.