he Grum botnet, also known by its alias Tedroo and Reddyb, was amostly involved in sending pharmaceutical . Once the world's largest botnet, Grum can be traced back to as early as 2008. At the time of its shutdown in July 2012, Grum was reportedly the world's 3rd largest botnet, responsible for 18% of worldwide spam traffic.
Grum relies on two types of control servers for its operation. One type is used to push configuration updates to the infected computers, and the other is used to tell the botnet what spam emails to send.
In July 2010, the Grum botnet consisted of an estimated 560,000–840,000 computers infected with the Grum. The botnet alone delivered about 39.9 billion spam messages in March 2010, equating to approximately 26% of the total global spam volume, temporarily making it the world's then-largest botnet. Late in 2010, the botnet seemed to be growing, as its output increased roughly by 51% in comparison to its output in 2009 and early 2010.
It used a panel written into control the botnet.