Objective Development has released Little Snitch 4.3 with improved detection of program modification, performance improvements, and bug fixes for the network traffic management utility. Little Snitch now checks whether a program has been modified or tampered with (even if it lacks a valid code signature), improves the appearance of Dark mode in macOS 10.14 Mojave, reduces CPU load during DNS lookups and while inactive, improves overall performance for large rule sets, automatically combines similar rules into a single row, and ensures data rates shown in Network Monitor match the values in the status menu.
To improve performance, Little Snitch 4.3 has switched to a new configuration file format that is not compatible with older versions of Little Snitch. When updating to Little Snitch 4.3, the old configuration file is left untouched in case you want to downgrade. ($45 new, free update, 41.7 MB, release notes, 10.11+)