Four arrested in major international anti-malware operation: Europol

Europol called it "the largest ever operation against botnets, which play a major role in the deployment of ransomware", adding that it involved arrests in Armenia and Ukraine, as well 16 police searches in four different countries.

In addition to the four arrests, eight fugitive suspects linked to the case will be added to Europe's Most Wanted list.

"The actions focused on disrupting criminal services through arresting High Value Targets, taking down the criminal infrastructures and freezing illegal proceeds. This approach had a global impact on the dropper ecosystem," Europol said, referring to a type of software used to insert malware into a target system.

The servers targeted were located in several European countries, as well as the United States and Canada.

The agency said the operation, dubbed Endgame, was ongoing and that more arrests were expected.