A hack can be a sore crack at the end of the lips, a scab is obviously when something bled and is healing up!
(as if you didn't know!)
I presume it's difficult to tell what it is cos looking up one's pwn nose is a bit problematic lol xx
I presume, what we as children used to call a "bogey"....perhaps.
If that is so and it is large and it smells, then it may need removing with forceps.
No big deal......see your GP.
Are you female and Irish?