A botnet responsible for nearly a fifth of the world's spam email has been taken offline.
The botnet known as Grum took cyber warriors three days to take offline by battling servers based in Russia, Panama and the Netherlands.
"I am glad to announce that, after three days of effort, the Grum botnet has finally been knocked down. All the known command and control (CnC) servers are dead, leaving their zombies orphaned," wrote researcher Atif Mushtaq for FireEye Intelligence Lab.
The size and scale of the Grum bot made it the world's third-largest, but only because the world's biggest spammers (like the infamous Rustock botnet) have slowly but surely been shut down.
The shut-down came through a variety of measures, including pressure on ISPs and upstream providers which Mushtaq reckons means that there are "no longer any safe havens".
"Most of the spam botnets that used to keep their CnCs in the USA and Europe have moved to countries like Panama, Russia, and Ukraine thinking that no one can touch them in these comfort zones," he concluded.
"We have proven them wrong this time. Keep on dreaming of a junk-free inbox."