It’s one thing to fear your passwords and credit card details being stolen, but what if that wasn’t all you had taken from you? What if your computer wouldn’t boot and was made next to impossible to recover? That’s just what a new form of malware does.

Called “Shamoon”, the new viral attack threatens your online integrity by stealing sensitive information, but then goes a step further by overwriting the master boot record of a computer, rendering the machine unusable and making it difficult to repair.

Without the master boot record – or with a rewritten record, such as the type the Shamoon malware forces on its victims – computers can’t load the way they normally would, as this is the file that tells a computer where things are.

When the file doesn’t function the way it’s supposed to, it’s like you’ve lost access to your copy of Windows, with all of your passwords, preferences, and anything else associated with the operating system.

In fact, losing your operating system isn’t all that could happen, with documents, photos, music, videos, and other files rendered next to impossible to recover with a damaged boot record.

“Early analysis indicates that Shamoon is very dangerous,” said Kaspersky Australia’s Sam Bryce-Johnson, adding that “the malware steals private data and essentially makes the victim’s computer useless.”

While such an aggressive payload is rare for forms of malware, it’s not unheard of, and the best protection is having a form of internet security kept up-to-date with current viral signatures.

“Viruses don’t see geographical borders, meaning malicious code that exists on the other side of the world can attack computers in Australia almost immediately,” Bryce-Johnson said.

“If users are not prudent in practicing good security habits then they are easy targets for cyber criminals scattered throughout the globe.”