"The worry is that this kind of attack could be used on more high-profile targets," he said.

One of the things that makes the attack particularly nasty is that it's very hard to protect against.

"As far as I know, the only real defense you have is to ask your upstream provider to filter [the malicious traffic]," he said. "It's not something the victim can do by themselves. They need cooperation from the provider."

The DNS system, a kind of directory assistance service for the Internet, has come under increased scrutiny over the past year, when hacker Dan Kaminsky discovered a serious flaw in the system. That flaw, which has now been patched by makers of DNS software, could be exploited to silently redirect Internet traffic to malicious computers without the victim's knowledge.

DNS-OARC has on how to prevent BIND DNS servers from being used in one of these attacks. Microsoft was unable to immediately provide information on how to mitigate this particular attack on its own products, but its guidance on deploying secure DNS servers can be found