By itself, the code does nothing useful nor dangerous.
After manually deobfuscating:
func = function() { var var5 = {}; var5[100] = "_0x32lsj9"; do { var5[100] += var5[100][Math.floor(Math.random() * var5[100].length)]; } while (var5[100].length < 31); return function() { return var5[var5[100]]; } }; func()()()()()()()()()()()()()()()(); Looks like more an attempt to keep your browser busy on the chained calls.