A method for replacing an illegitimate copy of a software program with a legitimate copy is provided, the method including: determining metadata of a first software program running on a computer; transmitting a patch from a first server to the computer, if the metadata does not correspond to metadata of a legitimate copy of the software program; generating a second software program by replacing at least a part of the first software program with the patch; displaying a graphical user interface using code components of the patch and asking a user for an authentication token; acquiring the authentication token from a second server; verifying the authentication token; and labeling the second software program as a legitimate copy if the authentication token is verified. A corresponding system is also provided.