The person who "cracked" the keylogger often inserts their own code [1]. Instead of you monitoring a device, the cracker may end up monitoring you , capturing your passwords and banking details [2].
Searching for or cracks for software like Refog Keylogger on sites like 1337x is highly risky and generally discouraged [1]. While these "Ahmed New" style posts claim to provide free access, they are frequently used as delivery mechanisms for malware, spyware, and ransomware [1, 2]. The Risks of Using Cracked Keyloggers refog keylogger 518934 serial 1337x ahmed new