Germany will take action against Russia for the latter's successful attempt in 2015 to hack into emails of chancellor Angela Merkel and some Members of Parliament (MPs) of the Bundestag or German Parliament.

Merkel on Wednesday said Russia will pay a price for the exploit in which hackers under the command of Russia's GRU (Glavnoye Razvedyvatel'noye Upravleniye, or the military foreign-intelligence service) managed to completely copy two of Merkel's email accounts containing correspondence dating between 2012 and in 2015. 

The GRU operation that hit the Bundestag involved an aggressive cyberattack called Sofacy or APT 28, which also infiltrated other NATO members and temporarily shut down French TV station TV5Monde.

"We always reserve the right to take measures, including against Russia," said Merkel at the Bundestag.

German prosecutors have issued an international arrest warrant for a Russian hacker named as Dmitri Badi. This man is believed to work for the GRU.

Merkel said the German intelligence community has "hard evidence" Russian intelligence launched the 2015 hacking attack. Merkel's testimony is the first official confirmation of claims extensively reported by the German press this week.

"I can honestly say that it pains me," said Merkel.

She then vented her frustration at Russia's "outrageous" behavior.

"Every day I try to build a better relationship with Russia, and on the other hand there is hard evidence that Russian forces are doing this," she pointed out.

She said she's taking this event "very seriously because I believe this has been very thoroughly investigated." Merkel noted the hack of her emails is a hybrid warfare strategy by Russia "we can't ignore that includes cyber attacks, disorientation and manipulation of facts."

And to drive home her point Russia will suffer consequences, Merkel brought up the murder in Berlin in 2019 of a former Chechen commander by a Russian man working for Russian intelligence.

German prosecutors are convinced Russian intelligence is behind the shooting death of Zelimkhan Khangoshvili, a Georgian who fought against Russia in the Chechen War. Khangoshvili was murdered in a central Berlin park in broad daylight. A Russian national has been arrested for the killing. Prosecutors said he acted on behalf of the Kremlin.

Germany later expelled two Russian diplomats over the murder and accused the Kremlin of refusing to cooperate with investigations into the murder of Khangoshvili.

"I will work for a good relationship with Russia because I think there's good reason to continue these diplomatic efforts," said Merkel. "But of course this doesn't make it easy."