British National Crime Agency and FBI have arrested the alleged leader of the Dridex botnet, Andrey Ghinkul. Dridex is a botnet that steals banking credentials to then deviate money to bank accounts controlled by criminals. Infection method is through social engineering and emails with infected attachments. Dridex has obtained 50 M dollars, 30 of them from British victims.
UPDATE 10/30/2015 - AnubisNetworks Labs has published a report describing the efforts undertaken during this investigation led by the NCA, with our participation, to track this malware and exploit its communication channels. See link.