WA Consumer Protection said the scammers sent malicious software through an innocuous looking email, usually in the form of an attachment or a hyperlink.
Once clicked, the ransomware begins downloading without the user�s knowledge and will then lock that person out of their computer.
The scammer will then ask for payment to unlock the computer.
Consumer Protection commissioner Anne Driscoll said the reported cases might be the tip of the iceberg, as many would go unreported.
�Ransomware can be devastating not only to home computer users but small business owners who don�t have the time, expertise or resources to deal with the problem,� she said.
�I urge West Australians not to pay money to |cyber criminals if their computers are infected by ransomware, as the scammers are likely to come back for more money.
�Instead, use a different device to search online for a solution or seek help from a local computer technician.�
Consumer Protection has received more than 30 reports of ransomware attacks in the last year.
Visit www.scamnet.wa.|gov.au for more information.