WebProNews

A study shows most zombie attacks on computer systems start at machines using America Online.

Using data collected during real DDoS attacks, the security company Prolexic Technologies has found AOL to be the most infested network on the Internet.

Of the attacks it recorded over the last six months, Prolexic found through its Intrusion Prevention Network that 5.32 percent came from aol.com addresses. Among US based networks, attacks from AOL machines were more than 11 percent of the total.

T-Mobile's German parent, Deutsche Telecom, and French ISP Wanadoo were behind AOL in the top three infested networks. Zombie machines pose a problem to businesses and individuals.

When used to carry out a Distributed Denial of Service attack, those machines, controlled centrally by a malicious individual or group, can quickly knock down an unprotected web site or network.

It appears those networks named can do a better job of filtering their networks and detecting zombies in their domains. DDoS attacks have become a weapon used by criminals to extort funds from businesses like banks or gambling portals, according to Reuters.

Spammers also use zombie machines to send out their mass mailings by the thousands. Many users whose machines have been compromised may not even be aware that they are running a zombie.

Users can better protect their hardware by running a personal firewall to block the open ports commonly exploited by criminal hackers and spammers.

David Utter is a staff writer for WebProNews covering technology and business. Email him here.