Techtool Pro 18 introduces the Security Check tool, which reviews a number of potential security vulnerabilities on your Mac. This article covers how to keep your Mac secure for the SIP Status check.
System Integrity Protection, or SIP, is a security feature of Apples macOS operating system, introduced in OS X 10.11. It protects your Mac in a number of ways, principally by preventing any system files from being altered, even by administrator users. If SIP is disabled, someone could theoretically gain administrator access and modify system files.
If the Security Check tool identifies that SIP is not enabled, it can be re-enabled using Terminal in Recovery mode. To enable SIP, first restart your Mac in Recovery mode. First, shut down your Mac. On Intel Macs, hold Command-R at startup to enter Recovery mode. On Apple Silicon Macs, start up your Mac and continue to hold the power button until the system volume and the Options button appear, and then click the Options button and follow the prompts.
For more information on Recovery mode, see this Apple knowledge base article.
Once in Recovery mode, choose Terminal from the Utilities menu, and enter the following command:
csrutil enable
After restarting your Mac normally, SIP will be enabled, making your Mac more secure.