OSLO (Reuters) - Hackers have infiltrated the Norwegian Parliament’s computer systems and extracted data, officials said on Wednesday, just six months after a previous cyber attack was made public. The attack by unknown hackers was linked to a “vulnerability” in Microsoft’s Exchange software, the parliament said, adding that this was an “international problem”. The latest attack was more severe than last year’s, parliament President Tone Wilhelmsen Troen told a news conference. “This is an attack on our democracy,” she said. “The severity is underscored by the fact that this is happening in the run-up to a parliamentary election and as parliament is handling a pandemic.” An investigation of what information had been extracted was ongoing, she added. The previous attack, made public in September, was launched by Russia, Norwegian foreign minister Ine Eriksen Soereide said the following month, an accusation Moscow denies. There was no evidence at this stage that the two attacks were linked, parliament said. Norwegians head to the polls in September. Microsoft did not immediately reply to a request for comment. Reporting by Gwladys Fouche; Editing by Terje Solsvik, Pravin Char and Alex Richardson