Cybercriminals have attacked PKO BP bank clients. Fraudsters have been sending false e-mail messages entitled "Payment confirmation".

The messages do not contain any text, but only attached PDF file named "pko-trans-details-170507-121204.pdf".

As reported by the Niebezpiecznik portal, when the file is being opened, it tries to establish a connection with the cybercriminals' server. If a user opens a file using Adobe Acrobat Reader in Windows, the connection to the server is blocked.

However, should the user open the file with another program, he or she may download the malicious file which will infect the computer.

PKO BP bank assures that they analyze every signal and information received from the clients and that every suspicious case is reported to law enforcement agencies and to international CERT teams.