Australia's electronic espionage agency has been directly linked to some of the most sophisticated malware discovered so far on the internet.

Top secret documents leaked by former United States intelligence contractor Edward Snowden and analysis by Kaspersky Lab security researchers suggest the Australian Signals Directorate has employed and may have helped develop elements of "Regin," a form of highly advanced malware described as a "top-tier espionage tool".

Malware, short for malicious software, is software used to disrupt the operation of a computer, gather sensitive information, or gain unauthorised access to or control of computer systems

Earlier this month Der Spiegel magazine published an extensive article on the US National Security Agency's cyber espionage operations based on documents obtained from Mr Snowden.

According to Der Spiegel, the NSA and its "Five Eyes" intelligence partners in the United Kingdom, Canada, Australia and New Zealand are developing offensive computer network attack capabilities that can target the critical infrastructure of potential adversaries.