The Australian Federal Police (AFP) has confirmed it is assisting the FBI in a global crackdown on computer malware which allows criminals to steal passwords, banking details and remotely activate webcams.

The FBI says Australians are being targeted in a global raid on users of the software program Blackshades Remote Access Tool (RAT).

"This software was sold and distributed to thousands of people in more than 100 countries and has been used to infect more than 500,000 computers worldwide," the FBI said in a statement.

The program has already been used by hackers to steal personal data and launch cyber attacks.

The FBI says the Blackshades RAT malware was uncovered during a previous international investigation called Operation Cardshop, which targeted "carding" crimes and offences in which the internet was used to traffic and exploit stolen credit cards and bank accounts.

Signs your computer may be infected: Mouse cursor moves erratically with no input from user

Mouse cursor moves erratically with no input from user Web camera light (if equipped) unexpectedly turns on when web camera is not in use

Web camera light (if equipped) unexpectedly turns on when web camera is not in use Monitor turns off while in use

Monitor turns off while in use Usernames and passwords for online accounts have been compromised

Usernames and passwords for online accounts have been compromised Unauthorised logins to bank accounts or unauthorised money transfers

Unauthorised logins to bank accounts or unauthorised money transfers Text-based chat window appears on your computer's desktop unexpectedly

Text-based chat window appears on your computer's desktop unexpectedly Computer files become encrypted and ransom demand is made to unlock files

"We spun off a new investigation and ultimately identified one of the Cardshop subjects - Michael Hogue - and Alex Yucel as the Blackshades co-developers," the FBI said.

"Yucel, the alleged head of the organisation that sold the malware, was previously arrested in Moldova and is awaiting extradition to the US."

The FBI says the malware performs unwanted actions on computer systems including hacking into social media accounts, recording keystrokes, accessing documents and photos and activating webcams.

This morning the AFP confirmed it was assisting the United States with the investigation, but a spokeswoman says the extent of its involvement cannot be revealed for operational reasons.

"The AFP continues to urge individuals to ensure they have the most up-to-date anti-virus software to protect themselves from malicious software," the spokeswoman said.

The US has also charged a group of Chinese military officials with corporate espionage, for allegedly stealing secrets from American companies.