The people arrested and interviewed are all suspected to be customers of a counter anti-virus platform and crypter service. These tools are used by cybercriminals to disguise their code from security software solutions, Europol said.
The operation, codenamed Neuland, was led by the Kriminalinspektion Mayen with the support of Europol’s European Cybercrime Centre and the Joint Cybercrime Action Taskforce, a specialised group of cyber investigators at EC3.
The first phase of the operation took place in April 2016 in Germany, while the second expanded to Cyprus, Italy, the Netherlands, Norway and the UK in June 2017, Europol said.
Europol's Internet Organised Crime Threat Assessment warned last year about the increasing misuse of legitimate anonymity and encryption services and tools for illegal purposes to avoid detection, investigation and prosecution by the authorities, it said.
Cybercrime expert Ian Birdsey of Pinsent Masons, the law firm behind Out-Law.com said: "Dealing with cybercrime is a team sport, requiring international cooperation. The techniques and methods that are being used by cyber criminals are making it increasingly difficult for authorities to identify and catch them, and the authorities need more resources to deal with what is a cyber arms race."