Police raid cybersecurity firm over Bulgaria's biggest data breach

Prosecutors have said they believe Boykov did not act alone and were now looking for instigators of the cyberattack and contractors they used.

Police investigating Bulgaria's biggest-ever data breach have detained a manager of a cybersecurity company, raided its offices and seized computers, they said on Wednesday.

The company, Tad Group, has become a focus of the investigation. Another of its employees, Kristian Boykov, is the only person so far charged with involvement in last month's cyberattack on the tax agency, in which nearly every Bulgarian adult's financial records were compromised.