Chinese hackers have successfully targeted Cambodia's Government ahead of the country's contentious national elections later this month, according to a new cyber security report.

Analysts from the US-based security firm FireEye detailed Beijing's suspected espionage activities in research released a fortnight before Cambodians go to the polls.

The FireEye report details how a well-known Chinese hacking group called TEMP.Periscope has targeted several key branches of Cambodia's Government, including the Senate and the ministries of foreign affairs, economics and finance, as well as opposition figures and local media outlets.

Benjamin Read, FireEye's senior manager for cyber espionage analysis, believes the Chinese group has managed to gain widespread visibility into Cambodia's elections and government operations.

"They've really extensively targeted a lot of different sections of Cambodia's society," Mr Read told the ABC.

"The Government, Cambodian media and Cambodian opposition figures — it's obviously of interest in the lead-up to the elections at the end of the month."

According to FireEye others compromised by the attacks include the Cambodian National Election Commission, Interior Ministry and diplomats.

On July 29, Cambodian Prime Minister Hun Sen is poised to clinch an almost uncontested election victory, and in recent times the pro-Beijing leader has ramped up his anti-America rhetoric.

Cambodia has also recently enjoyed a surge in Chinese aid, and unlike its close neighbour Vietnam is a strong supporter of Beijing's territorial claims to the contested South China Sea.

Mr Read says his firm has only uncovered evidence of Chinese intelligence gathering, rather than election interference, but believes the activity is disturbing nevertheless.

He says so far it appears the China-based hackers are just gathering valuable intelligence ahead of Cambodia's elections.

"We've gotten kind of numb to China's doing a lot of hacking and on one side it's not exceptional, it's activity we've seen from China before."

"But if you step back and say 'hey, this evidence means China can spy on a large swathe of Cambodian government and society', that is very serious".