A co-ordinated disinformation campaign targeting the Australian media has been directly linked to Russia and is ramping up ahead of the US presidential election, a report says.
Finnish analytics firm CheckFirst unmasked the influence campaign, dubbed Operation Overload, in June after a joint investigation with AAP FactCheck and dozens of other global media organisations.
The operation has targeted 15 local organisations, including AAP, the ABC, The Conversation, The Daily Aus, with at least 71,000 spam emails containing deceptive content about global events such as the Ukraine War and Paris Olympics.
CheckFirst's second report on the campaign has unveiled more evidence it's based in Russia.
CheckFirst chief executive Guillaume Kuster says some email accounts used have been accessed from Russian residential IP addresses.
The report found QR codes within the emails were created by an individual linked to a Russian marketing agency.
"That is a red flag," Mr Kuster told AAP.
"It's not proof of anything but it's one more hint at the fact that particular organisation is belonging to a wider-scope organisational effort."
He said it was unclear exactly who was behind the campaign or if it was state-backed but it appeared to be an attempt to trick fact-checkers into debunking and inadvertently amplifying fake content.
"Any publicity is good publicity," Mr Kuster said.
The number of emails has trebled since June, with the subject shifting to the US election and US newsrooms becoming the prime targets.
Mr Kuster said Australian newsrooms were targeted as they're considered part of "the global West".
While not illegal, the report said the campaign may violate the terms of service of email platforms prohibiting spamming, phishing, and creating misleading content.
Mathew Sussex from the Australian National University Strategic and Defence Studies Centre said Russia was interested in Australia due to its support for Ukraine.
"Australia is seen potentially as a bit of a test case of a stable democratic state where you can try out various attempts at disinformation, cyber-enabled political warfare, and see what works and what doesn't," he told AAP.
Dr Sussex said targeting fact-checkers was part of a sophisticated strategy of interfering with democratic elections, which included paying US social media influencers to produce pro-Kremlin content.
"And you know, if you can swamp fact-checkers and journalists with mis- and disinformation, then that's another piece of the puzzle," he said.
Dr Olga Boichak, a University of Sydney disinformation expert, said Operation Overload fits the Russian doctrine of reflexive control, which aims to alter an adversary's information environment.
She said overloading fact-checkers and journalists with deceptive content undermined two mechanisms that created facts in democracies, making it easier to spread disinformation.
"It's almost like flooding the signal with so much noise it becomes nonsensical," Dr Boichak told AAP.
The Department of Home Affairs is aware of Operation Overload, saying it had laws and "a robust framework" to combat influence campaigns.
"Foreign interference and espionage are among Australia's principal security concerns," a spokesperson told AAP.
"They threaten the things we value most about our country - our social cohesion, our trusted democracy, and our freedom of thought and expression."