If ASUS are even halfway competent (hardly a given in this context), it won't be reversible because it's not encryption at all but a one-way hash function.
(Digression: you might be able to guess a string that hashes to the same hash code, which'd let you log in; but the odds of it being the same as the user's real password are tiny. The reason this approach is considered the minimum acceptable standard nowadays is that it protects users who are silly enough to use the same password for multiple services. Even if you get their hashed password out of service X and are able to reverse-engineer some string with the same hash (after much computation), it likely won't let you into their account on service Y.)
I gather from reading this thread that they used to not obscure the stored password at all, which is several steps below awful. I hope that when they fixed that, they brought it up to something approaching minimum-acceptable-practice-for-the-last-couple-decades, which would be hashing not true (i.e. reversible) encryption.
