Following a recent hacking attack on the A1 telecom, the police stated on Monday that they had searched the home, computers, and mobile phone of an underage male based in Slavonski Brod County in eastern Croatia.

Last Wednesday, A1 Croatia reported a hacker attack to police, saying that some personal data of the A1 network’s users had been compromised but that information on their bank cards and accounts had not.

The company said that the names, addresses, personal identification numbers and phone numbers of “less than 10 percent of A1 Croatia users” were potentially compromised. They added that bank card and accounts information had not been stolen as these were stored in a separate, unaffected, database..

Immediately after the incident, A1 said they were “working intensively” to establish all the facts related to the security incident, and that all users whose personal data had been potentially compromised would be notified of the security breach.

On Monday, Croatian police said that their cyber security department had conducted an intensive investigation and that given that an underage person is implicated the authorities could not comment on the case in detail.

According to local media, the hacker had demanded 150 Ethereum coins, worth about $500,000, threatening that he would release the data on the dark web. They also reported that personal information from some 100,000 users of A1 services have been stolen.