Earlier this week a vulnerability was discovered in the MacOS High Sierra, the operating system used by MacOS 10.13.1 or higher versions.  The vulnerability which was first disclosed by a Turkish software developer Lemi Ergin through a tweet rather than following the more common procedure when researchers discover software vulnerabilities of contacting the software company privately to assist in creating a patch for the software vulnerability before it can become known to the general cybercriminal community.
In any event, Apple promptly issued a security patch to resolve the problem.  If you are a Mac user, you can use this link to go to Apple for more information about the security patch.  https://support.apple.com/en-us/HT208315
TIPS
It is critical to your security that you update your computer and other electronic devices whenever security patches and updates become available for the software that you use.  The best way to do this is to provide for updates to be automatically installed, but in any event, the important thing is to update your software as soon as patches are available.  Many significant data breaches including the massive data breach recently at Equifax could have been prevented if people had installed security updates that were already available to thwart cybercriminals attacking flaws in software for which security patches had already been issued.  Here at Scamicide we try to alert you when significant new patches are issued.