How does an unknown hacker crew build up enough power to take down the largest gaming networks in the world? It's a question that many observers have been asking, on the heels of the DDoS attacks that brought down Xbox Live and the PlayStation network on Christmas Day. Today, Brian Krebs has dug up an unconventional answer: routers. Krebs looked into Lizard Squad, the group behind the attacks, and found much of the group's DDoS capabililties came from home routers that had been remotely compromised. Using a recently discovered malware variant, Lizard Squad was able to turn common household routers into so-called "stresser" tools, which flooded the networks with bogus traffic, ultimately making them unavailable for legitimate gamers.

Routers are a notoriously easy target for malware attacks, thanks to a slow-to-nonexistent patch schedule and general neglect. A new vulnerability putting more than 12 million routers at risk was made public just days before the Lizard Squad attacks, although the crew does not appear to have made use of it. A number of Lizard Squad members have already been arrested, but many of the vulnerabilities they exploited have yet to be addressed. Until they are, it will be easy for groups like Lizard Squad to mount cheap and destructive DDoS attacks, and hard for networks to defend themselves.