The German government admitted on Wednesday that the Foreign and Defense ministries had been infiltrated by Russian hacking group APT28.
Citing anonymous sources, the German news agency dpa reported the group likely placed a piece of malware on a key government network. The malware could have remained the government's networks for as long as a year, security officials said, according to Deutsche Welle.
The German Interior Ministry confirmed the breach.
The targeted ministries had since taken necessary measures to investigate the attack and protect their data, the spokesman added.
How much data was intercepted over the time remains unclear.
Read alsoReport: Dutch spies caught Russian hackers on tape – VOAHackers reportedly infiltrated the government's "Informationsverbund Berlin-Bonn" (IVBB) network, a specially designed communications platform that sits separate from other public networks for supposed added security. It's used exclusively by the Chancellery, the German parliament, federal ministries, the Federal Audit Office and several security institutions in Berlin and Bonn, the former German capital where some ministries still have offices.
APT28, also known as Fancy Bear, has been linked to Russian military intelligence. The group was identified as the likely source of an attack on the German parliament in 2015, and NATO and governments in eastern Europe.
Read alsoU.S. intel chiefs warn Russia intending to meddle in midterm elections – mediaThe group's 2015 attack on the Bundestag was so far-reaching that the German government was forced to replace its entire IT infrastructure.
German officials had feared that a trove of private documents could be released ahead of last September's federal elections, as happened just before the final round of the French election in May. However, those fears proved unfounded.