It then uses the "offset_toPayload" value as an offset that it will read 283160 (45218h) bytes from the XLS file. The shellcode then enters a decryption loop to convert the embedded payload from ciphertext to cleartext. The algorithm uses the length of the ciphertext negated as the initial encryption key, which it bit rotates right by 1 to adjust the key for each of decryption. It will use this key to decrypt four bytes of the ciphertext with the XOR operation until all the ciphertext is decrypted. During each iteration of the decryption process, the algorithm will check to make sure the four bytes of ciphertext are not equal to the key or equal to zero before decrypting the ciphertext. The following table contains the first five rounds of the algorithm to explain the decryption process