PlayStation 3 Jailbreak Exploit Firmware 4.84 legit or not?

I am not an expert in jailbreaking PS3 and not even have I modded a PS3 before, But I've been looking to do it and now I find this. Shamefully the console i'm wanting to jailbreak was updated to what I think it is the last cfw version 4.84 (I am doubting because the PS3 is not even mine), So the only way I can take would be to install this exploit that at least would allow me to run backups just like an ordinary jailbreak of Playstation 3. The question now would be.. Do you really think that...

PlayStation 3 Jailbreak Exploit Firmware 4.84 legit or not?