ALMOST 30 Australian businesses, including 12 in Queensland, have been held to ransom in the past week by cybercriminals who lock up their computer files with unbreakable encryption.
Some businesses have paid the ransom of $3000 or more to unlock their files, rather than lose all their data, Detective Superintendent Brian Hay of Queensland's fraud and corporate crime group said.
Supt Hay said he expected there could be many more Australian victims of the malicious software, known as Ransomware, who have not reported the attacks to police.
"A lot of businesses can't afford the interruptions to their trade and will pay straight away," Supt Hay said.
The businesses known to have been attacked include medical centres in Brisbane and central Queensland, and medical, entertainment, clothing and insurance businesses around Australia.
Businesses have found their customer records have been locked after malware has been downloaded on to servers.
The criminals then send ransom emails demanding $3000 cash payment, to be sent to Hong Kong and China via Western Union, for release of the files.
An extra $1000 is demanded for every day the businesses delay paying.