Security researchers at FireEye and SpamHaus have shut down a botnet called Grum whose servers were mainly in Panama, Russia and Ukraine. The people controlling the botnet quickly worked to move the command and control servers to secondary servers, but a major server in Panama was successfully shut down.

A researcher at FireEye named Atif Mushtaq said that more than 20,000 computers were still part of the botnet but that after shutting down Grum they would soon be ineffective.

Find out more details on this story at BBC News.