If you still prefer using LockRattler to SilentKnight, there’s a chance that it will crash if your Mac is an Intel model without a T2 chip, particularly if it’s running macOS Ventura 13.3.1.

This is because one of the features in macOS that it relies on is the command tool eficheck. This was introduced in High Sierra to check the integrity and currency of EFI firmware, but isn’t used on Intel Macs with a T2 chip, or on Apple silicon Macs. It appears that eficheck has now served its purpose, and is in the process of going away. At present, it might have a misbehaving code signature, and crash when run, which will in turn crash LockRattler. You can check that using the command
/usr/libexec/firmwarecheckers/eficheck/eficheck --integrity-check
where you must be careful to ensure there’s a double hyphen before the option.

As the behaviour of eficheck is now unpredictable, I have built a new version of LockRattler which no longer uses it.

LockRattler version 4.37 is now available from here: lockrattler437
from Downloads above, from its Product Page, and via its auto-update mechanism.

I’m very grateful to Ole for reporting this, and to Marina and Remo for confirming it for me.