"I personally made lots of mistakes", Brooks, who edited Murdoch's News of the World and Sun papers from 2000 to 2009, told the Old Bailey court here.
The 45-year-old, head of News Corp's British newspaper arm until 2011, said she had agreed payments on a "handful of occasions" between 1998 and 2009, when she held senior roles at both publications.
Brooks made the remarks during her fifth day of testimony at Britain's phone-hacking trial. She has denied four charges including conspiracy to hack phones.
Her barrister, Jonathan Laidlaw, asked her: "Were there occasions where there were approaches [by public officials] for money for the exchange of information."
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She replied: "Yes".
"My view at the time was that there had to be an overwhelming public interest to justify payment in those very narrow circumstances to a public official being paid for information directly in line with their job," she said.
Laidlaw asked: "So there had to be an overwhelming public interest, and if there was not?"
She replied: "If there wasn't a public interest defence then it was not done because it was considered to be illegal."
In 2003 the paper published the headline "Bonkers Bruno locked up" after boxer Frank Bruno was admitted for psychiatric treatment.
Brooks told the court this was a "terrible mistake", and said she had a "complete blind spot" when agreeing the headline.
"He had not been well, and we talked to him about it and we did everything we could to make up about it," she said.
The headline had been spotted by her partner Ross Kemp and she phoned the newsroom to have it changed, she said.
Brooks said "balance went right out the window" in attacks on social work leader Sharon Shoesmith after the death of Peter Connelly - known as "Baby P".
The phone-hacking trial is about illegal payments to public officials, allegations of attempts to hide potential evidence and phone hacking - the illegal interception of messages by journalists at the News of the World and the Sun.
Murdoch shut down the 168-year-old News of the World in July 2011 amid public outrage over phone hacking.