BredoLab was a botnet originating from Russia and first reported in May 2009 before becoming prominent in August 2009 by rapidly gaining in size.
BredoLab's main form of attack was the inclusion of malware attatchments in viral e-mail spam. When these attachments were opened the computer was turned into a botnet controlled zombie. At its highest the botnet was capable of sending 3.6 billion of these e-mails every day.
The botnet also used the method of drive-by downloads, exploiting security vuneralbilities in software allowing it to bypass protections and allow downloads without the user being aware.
Parts of the botnet were leased to third parties who used these infected systems for their own purposes and it is estimated that the onwer made up to $130,000 per month from related activities.
Dutch law enforcement moved against BredoLab in October 2010 and siezed control of 143 command and control servers leased from LeaseWeb. They then used the botnet itself to send messages to users of infected computers informing them that they were part of the botnet.
The botnet is still partly intact with command and control servers still present in Russia and Kazakhstan.