Hackers gained access to PAP’s internal IT systems in late May and put out fake news about a partial mobilization of 200,000 men to be sent to fight in Ukraine. The story was immediately removed but re-appeared shortly afterward.

PAP CEO Marek Błonski said the attack, which occurred in the run-up to European elections, was intended to spread disinformation.

“We are in no doubt that the attack on PAP was a planned, deliberate act serving disinformation,” he said. “We are committed to clarifying the issue in cooperation with the appropriate state authorities.”

Błoński added that PAP’s news service is used by around 100 of the country’s biggest editorial offices and accounts for about 35% of all news output nationally.

A prosecution service spokesperson said an inquiry had been launched into “disinformation by disseminating false information… by an undetermined person or persons involved in or acting on behalf of foreign intelligence."

Anyone found guilty of the crime faces at least eight years behind bars.

Cyberwar

Following the attack, Poland’s digital affairs minister, Krzysztof Gawkowski, attributed the attack to Russian hackers .

He said that “everything indicates that we are dealing with a cyberattack directed by the Russians.”

“Let’s call it what it is,” the Gazeta Wyborcza liberal daily reported him as saying, “we are at cyberwar with Russia.”

Minister Gawkowski said that prior to the attack on PAP, Poland had experienced a spate of cybersecurity events on critical infrastructure that the security services had successfully thwarted.

The Rzeczpospolita daily reported in May that Poland is among the countries most frequently targeted by Russian hackers. The paper wrote that Polish companies experience almost 1,430 attacks per week, while in the Czech Republic the figure is as high as 2,000.