Personal data belonging to millions of Bulgarians has been stolen in a cyber-attack on the country’s tax agency.
According to a local cyber-security researcher, most adults in the country of seven million people are likely to have had some data compromised.
Bulgarian authorities have arrested a 20-year-old man on suspicion of involvement in the attack.
The country’s finance minister, Vladislav Goranov, has apologised in parliament for the breach.
Mr Goranov said anyone who attempted to exploit the data “would fall under the impact of Bulgarian law”.
“It is safe to say that the personal data of practically the whole Bulgarian adult population has been compromised,” said cyber-security researcher Vesselin Bontchev, assistant professor at the Bulgarian Academy of Sciences.
An email purportedly from the hacker behind the attack was sent to Bulgarian media on Monday.
As well as criticising the state of government cyber-security, it contained an offer of access to the stolen data.
The email claimed that information on more than five million people, as well as businesses, was taken in the breach.