WARSAW (Reuters) - Hackers broke into the computer network of the Polish president's office and attempted to spread a computer virus in the form of an email attachment, the president's press office said on Thursday.
Similar incidents have taken place at several other government offices this month, including the Defence and Foreign Affairs Ministries.
The internal security agency ABW had placed strict limits on Internet access at Prime Minister Donald Tusk's office after the cyber attacks were first detected.
The president's press office declined to discuss the details of the latest hacking incident, except to confirm it took place and an email with a "harmful contents" was being investigated.
Niebezpiecznik, a website specialising in covering cyber security, said it had been contacted by a hacker using the pseudonym Alladyn2 who claimed responsibility for the attacks on government networks.
The person was quoted as saying they were only meant to test the government's ability to withstand them.
The website included several screen shots of what it said were the contents of an email account of a high ranking official at the prime minister's office and a list of passwords used by its workers.
The attacks follow similar incidents in the Czech Republic.
(Reporting By Karolina Slowikowska and Dagmara Leszkowicz)