If you downloaded Linux Mint on Saturday, February 20th, you may have unknowingly downloaded a hacked version of the operating system.

According to a blog post on the Linux Mint site, hackers broke into the Linux Mint website at some point on Saturday and made changes in order to direct users toward downloading “a modified Linux Mint ISO, with a backdoor in it.” Using the hacked version could allow hackers to steal your private information. According to Linux Mint, the hack only affects those who downloaded the Linux Mint 17.3 Cinnamon edition from the Linux Mint website on Saturday.

“If you downloaded another release or another edition, this does not affect you,” the blog post states. “If you downloaded via torrents or via a direct HTTP link, this doesn’t affect you either.”

The Linux Mint website is down for the time being (aside from the blog, anyway) as the team works to re-secure the site.

The story behind the story: Backdoors are serious threats to your security and privacy in that they could allow hackers—or government entities, for that matter—to readily bypass security measures in place and access your personal data without your knowledge. So-called backdoors have been in the news a lot in the past week, largely due to Apple’s legal fight with the FBI, which wants the Cupertino company to circumvent certain security measures on a suspect’s iPhone.

What to do if you’re affected

First and foremost, you’ll want to determine whether this hack impacts you. Check the Linux Mint blog for instructions on how to tell whether the ISO you have is legit or if it’s been compromised. If you’ve got a hacked version, you’ll want to destroy ISO—Linux Mint’s developers recommends that you delete the ISO file, throw away any DVDs you burned it to, and wipe any USB drives you stuck the hacked ISO on.

If you installed the hacked version on your computer, you’ll also want to remove it from your PC: The Linux Mint team says to disconnect your PC from the Internet, back up your personal files, and install an un-compromised operating system. If you have it installed on a secondary partition, you can wipe that partition entirely instead. You should also change your login passwords for any important websites or services you use.

Linux Mint Forums at risk, too

In a followup blog post, the Linux Mint team says hackers got ahold of its forum database as well. If you have a Linux Mint Forums account, you’ll want to change your password for any website or service that has the same password as your forum account. (Using the same password for multiple sites is a recipe for security disaster—don’t do it.) The forum is currently down as of this writing, but you’ll want to change your forum account password as soon as it’s back up and running.

[Update, February 21, 2016; 6:30PM PST: As originally posted, this article stated the hack took place on Friday, February 20th. February 20, 2016, of course, was a Saturday, not a Friday. We've corrected the article accordingly and we regret the error.]