There's several ways. The easiest two would be to
1) open the map yourself with an mpq editor and check out the .j file or
2) post it here and make a request
if you chose number 1,
download an mpq editor (like mpqmaster), run it, open the map, extract "war3map.j" or "scripts/war3map.j", open the .j file, and search for cheats.
I usually search for "chat" cuase most cheats are activated or triggered when someone types something.
if you find a suspicious chat command (like -cheats<space><space>), search the trigger variable and follow it to find the action function.
Ex:
Code:
TriggerRegisterPlayerChatEvent(TRIGGER VARIABLE,PLAYER TO DETECT CHAT FROM,CHAT COMMAND, TRUE OR FALSE)
the third argument is what you wanna check. if it seems suspicious search the first argument to find TriggerAddAction(TRIGGER VARIABLE, function SOME FUNCTION)
then search for the SOME FUNCTION and see what it does. the true or false doesn't really matter in this situation.
it gets easier if you learn jass first though o.o