Security researchers have been collaborating with the law enforcement agencies for this operation.  Researchers from Proofpoint said that the hackers sent out waves of up to 350,000 Dridex-laced spam emails every day, while, researchers at Dell SecureWorks started working on a project to disrupt the monstrous botnet. It teamed up with law enforcement, and received legal permission to hack the botnet, according to the company. In United Kingdom, Mike Hulett from the NCA said: “This is a particularly virulent form of malware and we have been working with our international law enforcement partners, as well as key partners from industry, to mitigate the damage it causes. “Our investigation is ongoing and we expect further arrests to made.”