Authorities in Canada and Australia say police have conducted searches in two cities as part of an investigation of criminal networks that use a type of malicious software to gain unauthorized access to computer systems.

The international investigation is focused on a type of malware known as a remote access trojan, or R.A.T, which can be used to commit a range of offences including theft of personal information and intellectual property.

In Canada, the Canadian Radio-television and Telecommunications Commission, or CRTC, says the RCMP used a search warrant on Wednesday at an unidentified residence in the Greater Toronto Area.

Australian Federal Police say they executed search warrants Thursday at an address in Lara, about 60 kilometres southwest of Melbourne.

The U.S. Federal Bureau of Investigation is also involved with the investigation, according to the AFP and CRTC.

The CRTC says investigators were acting on tips from private cyber security firms but didn't identify them or provide names of individuals or companies under suspicion.