A 20-year-old man has admitted to police that he was behind one of the country’s biggest data breaches, in which the private details of almost 1,000 public figures were leaked.

The man, who lives with his parents in the central German state of Hesse and is still in the education system, told police he had acted alone and was not politically motivated.

He told investigators he had been driven instead by his annoyance at statements made by the victims of his attacks, including politicians, journalists and leading celebrities.

German politicians’ personal data leaked online Read more

The interior minister, Horst Seehofer, hit back at widespread criticism that authorities had been slow to solve the case and that he had been reluctant to keep the public informed.

He revealed that the hacker would not have been able to gather as much data as he had, if his victims had created more sophisticated passwords.

“Bad passwords were one of the reasons he had it so easy,” Seehofer said. “I was shocked at how simple most passwords were: ‘ILoveYou’, ‘1,2,3’. A whole array of really simple things.”

He said both politicians and the public needed to greatly increase their sensitivity towards cybersecurity. Saying such attacks would likely become more commonplace, Seehofer announced the recruitment of hundreds more cybersecurity experts to the police force, as well as the setting up of a round-the-clock IT crew who would use early warning system software to both prevent and recognise such attacks.

The hacker, who used the pseudonyms “G0t” and “Orbit”, was arrested on Sunday after investigators searched his home. On Monday, he confessed to the cyber-attack, prosecutors said. He is accused of spying, leaking data and the unwarranted publication of personal data.

Investigators traced the man through digital tracks he left on the internet, as well as by speaking to witnesses, including a 19-year-old man with whom the hacker had communicated via an encrypted messaging service. The hacker told him he had destroyed his computer to avoid detection, but police said they had recovered extensive evidence.

Investigators in Wiesbaden at the Federal Criminal Police Office (BKA) said they believed the man was not aware of the severity of his actions.

He has been released on the condition that he does not leave his parents’ house and continues to cooperate. Investigators said the man did not pose a flight risk and that therefore there was no need to hold him in custody.

If convicted, he faces a three-year prison sentence, although, because of his age, he is likely to be sent to a young offenders’ institute with an emphasis on re-education.

There is also speculation that the hacker will receive a mild sentence if he continues to cooperate with investigators, partly because he has provided a wake-up call to German internet security chiefs about chronic weaknesses in their systems and could potentially help them improve them at a time when Germany is struggling to recruit IT security specialists.

Georg Ungefug, a spokesman for the central office for fighting internet crime in Wiesbaden, described the hacker as having “extensive knowledge of computers”, with no official qualifications, but in possession of “considerable interest and a lot of time” to carry out his attack. “There is no evidence of a third party’s involvement,” he added.

The breach only came to light last Thursday, although the data – everything from private telephone numbers to email correspondence and family photographs – had been released in the style of an advent calendar on Twitter between 1 and 24 December.

First came details from the private accounts of television and YouTube stars, followed by data belonging to hundreds of politicians, including the chancellor, Angela Merkel, and the German president, Frank-Walter Steinmeier.

According to a report in the newspaper Bild, which quoted an unnamed investigator, the hacker was described as a nerd who had few friends and spent the majority of his time on the internet.

The BKA again said there was no evidence a foreign government had been behind the attack, with initial reports pointing the finger at Russia or China.

Speaking alongside Seehofer in Berlin on Tuesday afternoon, Holger Münch, the head of the BKA, said the government had received 60m emails last year alone warning of potential cyber-attacks. He said there was no evidence that the man had had accomplices, but said the BKA’s investigations into how he operated had only just begun.

“We assume that the perpetrator would have kept going and been prepared to dig out and release more information,” Münch said. “His motive appears to have been a general discontent over the public utterances of politicians and others who he wanted to show up.”

He said his perpetrator profile was typical of that of a “growing generation of adolescents … or kinderzimmertäter [play-room criminals] who don’t have to step out the door in order to carry out their deeds”.

Münch added: “From the preventive point of view one needs to assume that young people in their bedrooms are not necessarily just playing.”