Microsoft organized 35 nations on Tuesday to take down one of the world’s largest botnets — malware that secretly seizes control of millions of computers around the globe. It was an unusual disruption of an internet criminal group, because it was carried out by a company, not a government.
The action, eight years in the making, was aimed at a criminal group called Necurs, believed to be based in Russia. Microsoft employees had long tracked the group as it infected nine million computers around the world, hijacking them to send spam emails intended to defraud unsuspecting victims. The group also mounted stock market scams and spread ransomware, which locks up a computer until the owner pays a fee.
https://www.nytimes.com/2020/03/10/us/politics/microsoft-botnets-malware.html
Also see:
Microsoft takes down global zombie bot network
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.
https://www.bbc.com/news/technology-51828781
New action to disrupt world’s largest online criminal network
Today, Microsoft and partners across 35 countries took coordinated legal and technical steps to disrupt one of the world’s most prolific botnets, called Necurs, which has infected more than nine million computers globally. This disruption is the result of eight years of tracking and planning and will help ensure the criminals behind this network are no longer able to use key elements of its infrastructure to execute cyberattacks.
https://blogs.microsoft.com/on-the-issues/2020/03/10/necurs-botnet-cyber-crime-disrupt/