Many security experts believe that China is behind the cyber attack on Australia but there is insufficient evidence to substantiate the claim.
Meanwhile, security experts have asserted that China was behind the attacks as it was the only state capable of launching such a wide-scale attack with intensity. One cybersecurity expert said that the attackers' code was used in the past and had similarities with the attack against the Parliament House for which China was held responsible. The Australian Strategic Policy Institute said the attacks were 95% launched from China. But some experts have said it is difficult to pinpoint the source of the cyber-attack. ABC Australia noted that, according to the Council on Foreign Relations, China, Russia, and Iran are the top three states suspected of sponsoring cyber operations.