13 million MacKeeper users find their personal data exposed after a major breach within the software security system. Reuters

MacKeeper claims to be the most effective security software for Macs. However, a breach in its system has left 13 million users' personal data exposed in what is considered to be one of the most high-profile cases involving Apple's Macs.

MacKeeper is a controversial utility software designed as a form of antivirus for Mac users. The developer of the software, Kromtech, in the recent past, has amassed quite a lot of negativity from Mac users for the service it provides. While some claim the software works as advertised, many others have complained of malware and crashes.

The recent breach was first published on Reddit by security researcher Chris Vickery. Vickery claimed he came across the breach in a moment of boredom while browsing the search engine In his report on Reddit he stated: "The data was/is publicly available. No exploits or vulnerabilities involved. They published it to the open web with no attempt at protection."

Kromtech then made its own announcement regarding the breach, and claimed fixing "this error within hours" of its discovery. The company added: "Analysis of our data storage system shows only one individual gained access performed by the security researcher himself. We have been in communication with Chris and he has not shared or used the data inappropriately."

Kromtech has insisted that it has limited access to users' sensitive information and uses a third party for processing payments and other financial transactions. Consequently, the magnitude of the breach has been limited to details like names, IP addresses, product orders and other such data, it said.

However, given the magnitude of the data exposed and little or no knowledge of it prior to Vickery's discovery, many users are sceptical about the safety of their data. MacKeeper seems to have much more on its hands than just a simple security breach.