A new round of so-called "pharming" attacks is targeting the .com internet domain, redirecting some internet users who are looking for .com websites to web pages controlled by the unknown attackers.

The SANS Institute's Internet Storm Center (ISC) issued a warning this week about the new attacks, which corrupt some DNS (domain name system) servers so that requests for .com sites sent to those servers connect users instead to websites maintained by the attackers.

News of the new attacks comes amid increasing reports of pharming scams, and statistics that show at least 1300 internet domains were redirected to compromised web servers in a similar attack earlier in early March.

ISC advised network operators to block traffic to and from the IP addresses involved in the attack to stop the redirection, according to information posted on the ISC website.

DNS is a global network of computers that translates requests for reader-friendly web domains into the numeric IP addresses that machines on the internet use to communicate.

Internet users who rely on a poisoned DNS server to manage their web surfing requests might find that entering the URL of a well-known website directs them to an unexpected or malicious webpage.

Pharming attacks are similar to phishing identity theft attacks, but don't require a "lure", such as a web link that victims must click on to be taken to the attack website.

The attacks have been increasing in recent months, as internet users become more savvy about traditional phishing scams and online criminal groups look for new ways to collect sensitive information or financial data from victims, according to The Anti-Phishing Working Group.