Microsoft has said it was part of a team that dismantled an international network of zombie bots.
The network call Necurs infected over nine million computers and one of the world’s largest botnets.
Necurs was responsible for multiple criminal scams including stealing personal information and sending fake pharmaceutical emails.
Cyber-criminals use botnets to remotely take over internet-connected devices and install malicious software.
The software can be used to send spam, collect information about what activity the computer is used for or delete information without notifying the owner.
Tom Burt, Microsoft’s vice-president for customer security and trust, said in a blog post that the takedown of Necurs was the result of eight years of planning and coordination with partners in 35 countries.
He wrote that the steps taken will “ensure the criminals behind this network are no longer able to use key elements of its infrastructure to execute cyber-attacks.”