The latest Anonymous attack, dubbed #OpMegaupload and spread via Twitter, tricks internet users into clicking on an Anonymous link that instantly launches a denial of service (DDOS) attack on US government websites or any site of the hacker group’s choosing.
Distributed denial of service attacks effectively flood the targeted websites with large volumes of traffic.
According to Sophos, Anonymous has claimed it’s attacking numerous websites in this way, including those belonging to the FBI, US Department of Justice, RIAA, MPAA and Universal.
The attack seems to be inspired by the FBI’s shutdown of file-sharing site Megaupload and the arrest of its founders.
The hacker group announced: "We Anonymous are launching our largest attack ever on government and music industry sites. Lulz. The FBI didn’t think they would get away with this did they? They should have expected us."
These attacks follow this week’s internet blackout, where thousands of sites protested proposed US anti-piracy legislation.
"In the past, Anonymous has encouraged supporters to install a programme called LOIC, which allows computers to join in an attack on a particular website, blasting it with unwanted traffic," said Graham Cluley, senior technology consultant at Sophos.
Join Anonymous’ zombie army, go to jail
"This change in tactic from Anonymous, which allows attacks to be launched by simply clicking on a link, means that internet users need to be extremely careful when clicking on unknown URLs or they could unwittingly be joining this latest zombie army.
"Don’t forget, denial-of-service-attacks are illegal," Cluley continued.
"If you participate in such an attack, you could find yourself receiving a lengthy jail sentence. I’m not sure if participants in this instance would get away with claiming that they innocently clicked on links by mistake, so make sure you always trust the links you click on, even if they’re shared by a friend on social networking sites."