Australian intelligence concluded that China was behind a major cyberattack on its parliament and major political parties in the lead up to the most recent elections, Reuters reported on Monday local time, citing five people with direct knowledge of the matter.
Reuters cited a classified report by the Australian Signals Directorate (ASD), the government agency responsible for cyber warfare, which is said to have determined in March that China's Ministry of State Security was behind the hacks.
Three of Australia's major political parties, including the Liberal, Labor, and National parties, were also impacted by the breach of the federal parliament's computer systems revealed earlier this year.
Reuters said it did not review the classified report, which included comment from the Department of Foreign Affairs. The report is said to have suggested keeping the findings a secret so that Canberra could maintain trade relations with Beijing.
Two sources told Reuters that independent members of parliament and other political parties were not impacted by the hack. They added that it was unclear when the attack began or how long it went on for.
Australia's most recent national elections took place on May 18 and Scott Morrison, Australia's conservative prime minister, pulled off a shocking win.
China's Foreign Ministry denied involvement in the cyberattack and told Reuters that the report is "just creating rumours and smearing others."
"When investigating and determining the nature of online incidents there must be full proof of the facts, otherwise it's just creating rumours and smearing others, pinning labels on people indiscriminately. We would like to stress that China is also a victim of internet attacks," the ministry said in a statement.
Morrison has not directly placed blame on China but suggested in February that a "sophisticated state actor" was behind the security breach. He did not explain how security detected the attack or what it did to combat the threat.
Senior intelligence sources told the Sydney Morning Herald at the time that the advanced malware used in the attack was only available to a small portion of countries, many of whom are friendly to Australia. The sources told SMH that left China and Russia as potential suspects.
China in February said suggestions that it was behind the attack were "baseless" and "irresponsible."
"Irresponsible reports, accusations, pressurizing and sanctions will only heighten tensions and confrontation in cyberspace and poison the atmosphere for cooperation," said China foreign ministry spokesman Geng Shuang.
China and Australia have also clashed on other issues, including election interference and major telecommunications provider Huawei, which is banned from supplying its technology to its 5g network over national security concerns.
China is Australia's largest trade partner, according to Reuters, and purchases more than 1/3 of the country's total exports.