Australians and multicultural communities have been the target of attempted assassinations and coercion from hostile countries.
At least three nations have plotted to harm people in Australia, the Australian Security Intelligence Organisation revealed.
"In a small number of cases, we held grave fears for the life of the person being targeted," Director-General Mike Burgess revealed in his annual threat assessment speech on Wednesday.
An Australia-based human rights activist was targeted by a foreign intelligence service that tried to lure them to a third country where plotters would be waiting to arrange an "accident" to seriously injure or kill them, Mr Burgess said.
The plot was foiled when ASIO stopped the travel.
A different hostile foreign intelligence service sought to harm or possibly kill one or more people on Australian soil in 2024, the nation's spy chief said.
It was part of a broader plan by the regime to silence critics of the government, including activists, journalists and ordinary citizens, he said.
The plotters were offshore in both cases and beyond the reach of Australian law.
Foreign regimes and authoritarian nations continued to monitor, harass, intimidate and force co-operation from people in Australia.
At least four countries have plotted forced repatriation - where people in Australia are coerced or made to return to their country of birth where they can face persecution.
It contributed to a culture of fear within diaspora communities, Mr Burgess said.
A dual-Australian citizen living in Australia "endured constant pressure from his former country’s authorities to return to face historical allegations".
"After he refused, the authorities began a campaign to break his will," Mr Burgess said.
Some authoritarian regimes were becoming more brazen and aggressive while other countries had "all but given up trying to harass members of their diaspora here".
"Others have stopped their spying, for now at least," he said.
The war in the Middle East hadn't inspired terrorism in Australia but had exacerbated division, elevated intolerance and undermined social cohesion", which made politically motivated violence more likely, Mr Burgess said.
The normalisation of violent protesting and intimidation increased the likelihood of violent acts, which was something the Jewish community was experiencing, he said, amid rising anti-Semitic attacks.
"I am concerned these attacks have not yet plateaued," the director-general said.
Radicalised minors can pose the same credible terrorist threat as adults, he said, revealing the median age minors first came into contact with ASIO was 15 and men made up 85 per cent of the agency's minor cases.
Minors were allegedly sharing beheading videos in the schoolyard and watching Nazi propaganda.
ASIO alerted the United States about a 12-year-old talking about live-streaming a school shooting and then moving to a church, synagogue or mosque.
Sabotage and espionage remain major concerns for national security, with foreign actors targeting defence personnel to learn coveted military secrets, especially as Australia develops and gains access to technology to power nuclear submarines.
Some defence personnel were recently given gifts that contained surveillance devices, Mr Burgess said, while hostile actors had tried to pre-position cyber access they could exploit in a future conflict.
ASIO worked with the US to shut down hackers targeting critical networks and shut down their access, including in Australia.
