Here's what MacKeeper is - and why you should avoid it
The details included names, phone numbers, passwords, user names, and more and were discovered by security researcher Chris Vickery who alerted Zeobit, the company which makes MacKeeper.
Vickery says he wasn't looking for the information and stumbled across it.
MacKeeper offers multiple security products for Apple Mac computers. The software, which is available as a download, comes with a free trial, followed by a subscription that starts at £5.95/month ($9.99) and goes all the way up to £14.95/month ($21.99).
However, many users claim that the software doesn't work as advertised. In many cases, customers say security threats are exaggerated or not detected at all.
Legal problems
The company has faced multiple lawsuits over the way its software works.
In January 2014, a set of plaintiffs from Illinois said that "neither the free trial nor the full registered versions of MacKeeper performed any credible diagnostic testing," which would invalidate one of the key claims of the software. It's unclear what the outcome of this lawsuit was, however.
In May 2015, Zeobit lost a $2 million (£1.3 million) lawsuit filed in Pennsylvania that claimed the company exaggerated security concerns on the Mac, forcing users into buying a full license for the software. The company agreed to set up a reimbursement fund for those who felt cheated by the software's claims but admitted no wrongdoing.
Zeobit has filed two lawsuits against people who spoke negatively about MacKeeper, claiming defamation. The first was filed in 2013 against the developer of ClearMyMac, a rival Mac cleaning client, and alleged that the company had created fake profiles, leaving unfavourable reviews.
The second case was about a YouTube video that described MacKeeper as a "scam."
Both cases were thrown out as Zeobit could not claim the defendants had damaged its reputation.
Pushy advertising practices
The company buys 60 million ad impressions per month, making it the heaviest advertiser to Mac users, according to PC World. The adverts include pop-ups, affiliates, and paid-for reviews that appear across the web. (For reference, there are between 80 and 100 million Mac users in total.)
The company (or people paid by Zeobit) has also created websites that promote favourable reviews, according to Apple blog The Mac Feed.
One of the top results for the search "MacKeeper" is a thread on Apple's forums titled "Do not install MacKeeper." The thread, which links to advice on how to uninstall the software, has been viewed almost 70,000 times.
Some people say MacKeeper is a "scam"
Reddit's r/Apple forum is also filled with posts about MacKeeper and its shady tactics.
"Run Malware Bytes Anti-Malware [a malware cleaning programme for Mac]," advised one user when asked how to delete the software. "MacKeeper is malware, there's no two ways around it."
Another thread created in September 2015, which has almost 4,000 upvotes, advises users on how to remove MacKeeper from a machine.
MacKeeper is not available from the Mac App Store but can be installed without a pop-up because Apple has granted Zeobit a developer ID. Business Insider has reached out to Apple to ask about the developer ID.
"We should start a petition to have Apple revoke their developer ID so it won't install on the default setting on Macs," wrote Reddit user Zlpoo. The comment received 700 upvotes. It's unclear if a petition was launched.
John Gruber, a well-respected Apple blogger, linked to the news that MacKeeper had exposed 13 million user accounts, saying: "That there are 13 million Mac users who've fallen for the MacKeeper scam is just heartbreaking. It's bad enough they were ripping people off in the first place - now they've exposed their passwords."
Other options are available
The leak is just the latest in a long line of mistakes from a company that should protect your Mac. Uninstalling MacKeeper - or, even better, not installing it in the first place - is the best option.
Macs can get clogged up with malware and viruses and keeping your machine clean is important.
Here are some alternatives:
Business Insider reached out to Zeobit and has not yet received a response. We will update the post when we hear back.