European cyber police have arrested a 32-year-old suspected of being the ringleader of a ransomware gang operating in Ukraine.
In raids across the country authorities seized laptops and arrested four other alleged hackers.
The gang are accused of successfully extorting “several hundred millions of euros” from victims in 71 countries.
The arrests are the latest efforts by international police to control the rising problem of ransomware.
Ransomware is malicious computer software that locks up systems until a ransom is paid to a hacker, usually in cryptocurrency like Bitcoin.
Europol says officers searched 30 properties last week resulting in the arrests of the five Russian speakers.
Investigators have not said which nationality they were.