Assuming you’ve downloaded the Little Snitch Disk Image (.dmg file) to your Downloads folder, open a new Terminal window and enter the following command to verify the cryptographic signature of the downloaded file:
shasum -b -a 256 ~/Downloads/LittleSnitch*.dmg
This command prints checksums of all Little Snitch disk images found in the Downloads folder. The checksums should be:
version 4.4.2:
6899b3aedc377c7d8a39eedce31341b2324d46fe78d0bd7eda23bd2ee9d61131