"The motivation appears to be purely criminal; much indicates that this was an attempt to extort a ransom from the company," Tusk told reporters.
He said the investigation was ongoing and that state security services were involved.
Tusk told a news conference in Warsaw that "no private company anywhere in the world can guarantee 100-percent protection" against cyberattacks.
Source: IAR/PAP
Click on the audio player above for a report by Piotr Urbaniak