Left-field antivirus firm Malwarebytes has launched the first ex-beta version of Secure Backup, a cloud security system designed to scan users’ files for infection before storing them in the cloud.

Is Secure Backup a conventional backup product for Windows PCs and Macs that happens to use the cloud or a security product in disguise? The design suggests it’s a mix of both but the ability to store and restore files in the event of a malware event is clearly a major attraction.

With the emergence of tricky forms of malware such as ransomware that lock (i.e. encrypt or otherwise render inaccessible) victims’ data, being able to reach to the cloud for a backup of these files becomes more than a convenience.

The key for this concept to work is that these files aren’t also infected with malware or restoring them from a cloud repository will simply reinstate the problem.

After scanning, Secure Backup sends all selected data files to a third-party data centre using SSL encryption, a security layer that is backed up by optional UltraSafe system that gives the user their own AES encryption key.

There are no limits to how many PCs can be backed up using a single license with Android and Apple iOS apps available to cover mobile backup.

Data comes in 50GB, 100GB and 200GB sizes with unlimited file versioning offered so that only the largest version of a file counts towards the data allowance. All backed up files are also archived in case the user regrets deleting them at a later date.

“Most people think secure backup solutions like Carbonite or Mozy can be a cure for a compromised machine after they have trouble,” said Malwarebytes’ founder and CEO, Marcin Kleczynski.

“Backups should be done when the machine is not infected, since restoring infected data will just re-establish the malware, and render the backup useless. The malware must be removed before backup.”

Secure Backup is relatively expensive for a market that expects free file synchronization to the cloud, albeit without the retained encryption key and large store offered by Malwarebytes.

The 50GB package costs $29.95 per year, while 100GB costs $59.95 per year and 200GB $119.95 per year.

Some people will complain that external drives are cheaper and the need to run scheduled backup is a bit old-fashioned when users increasingly set cloud drives as the default storage directory.  But it will appeal to specific types of user, for instance small business users who could use it in addition to offline backups.

Malwarebytes is better known for its antivirus software which despite being generally well regarded has not been without its problems. Last month, the firm had to apologise after a corrupted file in software update caused its software to identify Windows systems files as Trojans.