Stopping the Offensive Use of Patents Act or the STOP Act - Amends the Leahy-Smith America Invents Act to remove the eight-year sunset provision with respect to the transitional post-grant review program available to review the validity of covered business method patents, thereby making the program permanent.

Expands the term "covered business method patent" to include a patent that claims a method or corresponding apparatus for performing data processing or other operations used in the practice, administration, or management of any enterprise, product, or service, except technological inventions. (Current law limits the program to financial products or services.)

Requires the Director of the U.S. Patent and Trademark Office (USPTO) (the Under Secretary of Commerce for Intellectual Property) to work with and support intellectual property law associations throughout the United States, within established pro bono programs, to assist financially under-resourced resellers, users, implementers, distributors, or customers of an allegedly infringing product or process.