Exploit nonspecific host intrusion prevention/detection methods, systems and smart filters are described. Portion of network traffic is captured and searched for a network traffic pattern, comprising: searching for a branch instruction transferring control to a first address in the memory; provided the first instruction is found, searching for a subroutine call instruction within a first predetermined interval in the memory starting from the first address and pointing to a second address in the memory; provided the second instruction is found, searching for a third instruction at a third address in the memory, located at a second predetermined interval from the second address; provided the third instruction is a fetch instruction, indicating the presence of the exploit;provided the third instruction is a branch instruction, transferring control to a fourth address in the memory, and provided a fetch instruction is located at the fourth address, indicating the presence of the exploit.