Ransomware disguised as an installer of the new Microsoft Windows 10 operating system is encrypting Australian user and business computers.

The ransomware resides in an email that claims to be from Microsoft which offers a free upgrade to Windows 10. The email contains a zip file attachment, which contains a program labelled as the Windows 10 installer. However, if you run this program, it will encrypt any important files, including Word documents and photos on your computer.

If you receive an email offering a free upgrade to Windows 10, we advise that you delete the email and do not open it or any attachments.

Windows users interested in upgrading their computer can register via Microsoft’s official website. Windows 10 updates will then be facilitated by a program on your computer, not via an email offer.

Business users should check upgrades with their IT departments, and not attempt to perform such activities themselves.