Mitigating ROP attacks

Mitigating return-oriented programming attacks. Program code and associated components are received and loaded into memory. From the program code and associated components, a predetermined number of sequences of machine language instructions that terminate in a return instruction are selected. The sequences of machine language instructions include: machine language instruction sequences that are equivalent to a conditional statement "if-then-else return," sequences of machine language instructions corresponding to known malicious code sequences, and sequences of machine language instructions corresponding to machine language instructions in known toolkits for assembling malicious code sequences. For each selected machine language instruction sequence, memory blocks containing the selected machine language instruction sequence are rearranged using address space layout randomization (ASLR); then, upon expiration of an expected time interval required to locate the selected machine language instruction sequence by inspecting the rearranged memory blocks, the rearranging is repeated, thereby mitigating ROP attacks.