A screenshot for my favorite hex editor, HxD.
[0x12, 0x34, 0x56, 0x78]
Based off the example by the HxD author
Unfortunately, the selection size is limited to 0x1000 for performance reasons.
Download from releases and add to
C:\Program Files\HxD\Plugins. Create the folder if it doesn't already exist
This is only supported on HxD 188.8.131.52 but it will still work on other versions.
Compile the solution in
Examples\C++ with VS2019