There are two issues in play here: (1) what to do about any problem(s) caused by this mystery plist, and (2) which program does it belong to.
Limiting myself here to the latter, I agree with Artie that it's most likely NOT LittleSnitch, as this utility contains clearly recognizable strings like 'LittleSnitch or 'LS'' in its plists (personal observation). Apparently current LS versions no longer contain the string '23' (e.g., at.obdev.LSD.plist or at.obdev.LittleSnitchConfiguration.plist).
Google produces only a few (fairly recent) hits when searching for 'a23t.mk4e.plist'. My personal favorite for the source program is
Mortal Kombat 4 Enhanced.
