Interior Minister Horst Seehofer said in a statement that an initial analysis into the breach showed that information had been obtained through "wrongful use of log-in information for cloud services, email accounts or social networks."
Seehofer added that there was no evidence to show the lower house of parliament's computer systems had been affected.
Politicians from Germany's far-left Linke party were the first to confirm they had been compromised, but then it snowballed as details from almost all parties were found to have been leaked.
"I can confirm that there has been an incident", the Linke spokesman said, adding that Dietmar Bartsch, leader of the party's group in Germany's lower house of parliament, was personally affected.
Public broadcaster ARD television said earlier on Friday that hackers had posted personal data from hundreds of German politicians from major parties, including credit card details and mobile phone numbers.
Deutsche Welle reported that all political parties have been targeted apart from the far right AfD party.
Euronews contacted AfD who said they are not responsible for the hack.
“Are you kidding?” was their exact response.
And, as far as they can tell, the information of AfD members have not been exposed. However, the party says “we did not check the files yet”.
The Green party were one of the organisations affected.
Michael Kellner, Business Manager of Bündnis 90/DIE GRÜNEN said in a statement that the party were letting hacked members know about the incident and "recommends that all persons concerned file criminal charges."
The statement also expressed irritation that the party learned about the breach through internal channels and "not through the relevant security agencies."
How did this begin?
A twitter account with 17.7 thousand (currently) followers released personal information in an 'advent calendar' style - one dump of hacking 'goodies' every day until Christmas Eve.
The final door on the 24th was reserved for the centre-right alliance CDU/CSU.
The account was active until late Friday morning and is now suspended.
In a statement sent to Euronews by Twitter, the platform said:
"Posting a person's private information without their permission or authorisation is a direct and serious violation of the Twitter Rules. We also recently updated our Rules to prohibit the distribution of any hacked material that contains private information, trade secrets or could put people in harm's way."
Whether the information will be in any way compromising remains to be seen and we are reaching out to those affected to asses their fears, although in a presser this morning, the German government stated that nothing sensitive had been released.
The German Federal Office for Security in Information Technology tweeted that they are "intensively examining the case in close cooperation with other federal authorities."
"The National Cyber Defence Centre has taken over the central coordination. According to the current state of knowledge there is no concern of the governmental networks," the tweet continued.
Euronews telephoned a number of German politicians using numbers that were found in the leaked documents. One of whom, Jana Schimke of the CDU, said she didn’t even know she had been hacked, but realised that since our journalist had been able to make such a call, it suggested that she had.
Patrick Sensburg, also of the CDU, confirmed his office had been the victim of a phishing attack.
Just after midday CET, the CDU told Euronews the following: "Research so far has shown, that the information was not taken from our database."
How sophisticated was the attack?
James Chappell, founder and Chief Innovations Officer for digital risk company Digital Shadows told Euronews that it was "definitely on the more sophisticated end."
What can organisations do to prevent these attacks?
"The types of protections really have to be quite broad, if you look at the attacks on the UK parliament last year we saw a lot of personal advice going out to MPs about how they can protect themselves, certainly that's going to happen in this case although it's kind of closing the stable door after the horse has bolted," says Chappell.
"It's all about educating people on how to be secure, and I'm sure the BSI in Germany will focus a lot of efforts in trying to minimise the impact of this."
Bundestag member Patrick Sensburg spoke to Euronews on taking precautions with ones personal data.
Not only politicians got hacked
Patrick Gensing, a journalist with Tagesschau, was among dozens of German reporters who had their information leaked.
Gensing said this was not the first time he had fallen victim.
“I already had problems, few years ago, [hackers] tried to find my private address and print it on right-wing Internet sites so that’s nothing new for me. Now, it’s much bigger because many politicians are affected so I think it will be taken much more seriously now,’ he said.
Gensing mainly reports on right-wing extremism in Germany and suspects that’s why he’s a target for it.
“Every day, I get dozens of e-mail threats. People call us Lugen Presse or “lying press,” a term used in the Nazi times.”
"For most of them (the leaks) weren't that bad, because it was only the mobile, for example. However, a few (journalists) were hit hard, because the hackers published personal documents like passport data or from health insurance information. Vaccination papers, pictures, address books," Gensing added.
What is the status of the investigation into the attack?
Germany's Federal Office for Information (BSI) is investigating the attack. It said in a statement on Friday evening that it remained unclear if the compromise was due to a hack or leak.
It added that authorities are probing all possibilities and that there is no evidence yet of a successful cyber attack on government networks.
The BSI said that the personal data of celebrities and politicians have been published via Twitter since December.
"Since December 20, 2018, a large number of documents and personal communications from former and current politicians of all federal levels have been made publicly available on various download platforms in several steps," it read.