Is it forbidden to benefit from the internet after decrypting it to operate it for free, and what is the ruling on programs and files that have been downloaded using it?

It is not permissible to benefit from a company's service without its permission, as this constitutes an infringement of its right. One must immediately stop doing so and pay the company the value of what has been utilized. If that is not possible, then the equivalent value must be given to the needy or for public welfare. As for programs and files that have been downloaded, there is no harm in benefiting from them if their owners permit it.