A multi-national law enforcement operation has resulted in the takedown of 53 domains associated with Distributed Denial of Service (DDoS) attacks and the arrest of four people suspected of providing DDoS-for-hire services.

Operation PowerOff saw police and cybersecurity agencies from 21 countries involved in coordinated enforcement and prevention measures against the threat of DDoS attacks.

In a statement, published on April 16, Europol described DDoS-for-hire attacks as “one of the most prolific and easily accessible trends in cybercrime” because they enable individuals with little technical knowledge to follow step-by-step tutorials to execute cyber-attacks.

“These attacks inflict significant harm on businesses and individuals across the globe by targeting servers, websites, or online services and making them inaccessible to legitimate users,” the agency added.

The operation disrupted illegal booter services, the infrastructure which made DDoS-for-hire attacks possible, while it also disrupted technical infrastructure used to support DDoS attacks, which included servers and databases.

Europol said that the seizure of the infrastructure has hindered the targeted DDoS-for-hire services and has prevented further victims from being targeted and disrupted by attacks.

The operation also seized databases, which provided data on over three million criminal user accounts. This resulted in four arrests and 53 domains being taken down, plus the removal of over 100 URLs advertising DDoS-for-hire services from search engine results.

Law enforcement also used the information gleaned from DDoS-for-hire user accounts to distribute 75 000 warning emails and letters to users of the services, plus additional warnings posted to cryptocurrency and blockchain platforms cyber criminals use to pay for hiring DDoS attacks.

“The FBI through its unique authorities, world-class capabilities, and enduring partnerships continues to defend against the cyber threat,” said an FBI statement on Operation PowerOff

“Partnerships are critical because there is no one government or private sector entity that can address the range of cyber threats we face alone,” the agency added.

The full list of countries involved in the joint action, which is still ongoing, is:  Australia, Austria, Belgium, Brazil, Bulgaria, Denmark, Estonia, Finland, Germany, Japan, Latvia, Lithuania, Luxembourg, the Netherlands, Norway, Poland, Portugal, Sweden, Thailand, the United Kingdom and the United States.