The ARA newspaper has been able to access a list of the documents affected by the computer attack at the Universitat Autònoma de Barcelona (UAB) which contains more than 650,000 folders and files. The attack has been perpetrated with a ransomware - a malicious software that encrypts the victim's documents and demands a ransom to be able to access them again - called PYSA. According to the computer security consultant José Nicolás Castellano, and as the ARA has been able to contrast, the attackers are demanding 60 bitcoins (about three million euros) to release the hijacked files, but UAB sources say they have no record of this because, following the recommendations of the Cybersecurity Agency of Catalonia, they have not contacted the attackers and have no intention of paying.