According to German public broadcaster RBB, hackers have published personal data from hundreds of German politicians and political parties.
A spokesperson of German Chancellor Angela Merkel described the hacking attack as a "very, very serious incident."
The German Federal Office for Information Security (BSI), the Federal Criminal Police Office (BKA) and the Federal Prosecutor General have launched investigations. "According to the current state of knowledge, the governmental networks are not affected," the BSI announced on Twitter.
The attack affected all political parties represented in the German parliament (Bundestag) except the far-right Alternative for Germany (AfD). Data records of politicians like Chancellor Merkel and German President Frank-Walter Steinmeier and also of journalists, musicians and television presenters have been posted online by the hackers.
According to RBB, the stolen data had already been published last year via an anonymous Twitter account belonging to a platform whose operator is said to be based in Hamburg. "Why nobody took note of the leaks until Thursday evening is puzzling," said Michael Goetschenberg, the responsible journalist at RBB.
The published data included mobile phone numbers and addresses as well as very personal data like identity card numbers, credit card information, holiday pictures or internal documents of political parties.
According to Goetschenberg, "everything that hackers have been able to get their hands on seems to have been put on the internet."
German Justice Minister Katarina Barley said it was a "serious attack," adding that the perpetrators "want to damage confidence in our democracy and institutions."