I have a file with all those hex numbers like I said: 4d 2c 07 2c 77 b3 77 b3 74 81 9d 59 9d 5f 5a 9e 50 94 4e 8a 4e 8a 4e 8c 43 3c 28 1f 1d 5a 3b fe 3a f1 59 c0 9d f3 54 e2 b2 82 da 68 c1 9b ef bf 9d 59 92 a0 2a 6d 29 ed 29 ed 29 ed 29 ed 29 ed 20 e4 13"
The "decrypted" result of the file is every hex number is the result of substracting from itself the next hex number.