Rootkits are a particularly dangerous type of malware because they
attack deep within a computer system, often at BIOS level, and are very
hard to detect. Once installed, there are a number of ways in which they
can cause damage to you and your Mac. However, there are anti-rootkit
tools that can detect and remove them. In this article, we’ll explain
what a rootkit is, how you can avoid getting one on your Mac, and how to
remove a rootkit if you’re unfortunate to be attacked by one.

What is a rootkit?

As its name suggests, a rootkit is a set of tools that are installed at
root level on a computer, with the purpose of hacking into the system,
causing damage or stealing data. Rootkits come in different types, and
attack Macs as well as PCs.

*Root level gives highest administrator privileges on a computer*.

Full Blog article, he-

https://macpaw.com/how-to/remove-rootkit-malware

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David