Following Friday's arrest of a man suspected of carrying out the Spamhaus DDoS attack, Spain's Interior Ministry reported that the 35-year-old Dutchman was traveling around the country in a van he used as a mobile computing office.
The van was "equipped with various antennas to scan frequencies," the ministry said in a statement.
Additionally, two laptops and various documents relating to criminal activity were seized from the suspect's home, or rather, a bunker from which he operated.
Identified only by the initials SK, the man was arrested last week in Barcelona on suspicion that he played a role in March's distributed denial-of-service (DDoS) attack on The Spamhaus Project, which tracks the Internet's spam operations and maintains real-time databases that help weed out bogus emails.
Ars Technica identified the suspect as Sven Olaf Kamphuis, citing circumstantial evidence. Police have not yet released the man's name.
According to the Associated Press, the Dutch citizen is expected to be extradited back to the Netherlands within 10 days — a deal he agreed to during questioning in the National Court in Madrid on Saturday.
The Spamhaus attack, reportedly carried out by web hosting provider CyberBunker as payback for being blacklisted by the watchdog group, reached 300 Gbps. For comparison, a normal DDoS attack that could take down a bank website weighs in around 50 Gbps. The March service disruption knocked the Spamhaus website and mail systems offline for several days.
Officers from the Netherlands, Germany, Britain, Spain, and the US participated in the investigation, Spain's Interior Ministry said.