HELSINKI—Finland’s domestic security agency said Thursday that the cybergroup APT31, which is generally linked to the Chinese regime, was likely behind a cyberspying attack on the information systems of the Nordic country’s parliament. The Finnish Security and Intelligence Service, known by the abbreviation Supo, said it had “identified a cyber espionage operation targeted in 2020 against parliament with the aim of intruding into parliament’s IT systems.” The agency added that “according to Supo intelligence, APT31 was responsible for the attack.” It didn’t mention China by name or the group’s alleged links to the regime in Beijing. The statement was also posted on the agency’s Twitter site in English. Finland’s National Bureau of Investigation, NBI, said late December that it had started an investigation into suspected gross hacking and espionage attacks on the information systems of Eduskunta, the Finnish legislature. Among other things, some lawmakers’ email accounts were compromised. Parliament has …