(ShareCast News) - A 17-year old boy has admitted seven hacking offences linked to the TalkTalk data breach in October last year.The teenager, who cannot be named for legal reasons, was arrested in Norwich last November following an investigation by the Metropolitan Police's cyber crime unit and charged with breaching the Computer Misuse Act 1990.The boy admitted the seven charges at Norwich Youth Court and sentencing has been adjourned to 13 December.In its final results for the 12 months to the end of March released in May, TalkTalk said it incurred one-off exceptional costs of £42m associated with the cyber attack.The company was fined a record £400,000 last month by the Information Commissioner's Office for failings that allowed a hacker to access customer data "with ease".The ICO's investigation concluded that the cyber attack - which resulted in the personal data of nearly 160,000 customers being accessed - could have been prevented if the telecoms group had taken basic steps to protect its customers' data.The news came as TalkTalk said on Tuesday pre-tax profit in the six months to the end of September rose to £46m from £14m in the same period a year ago.