The ever increasing complexity of distributed systems mandates to formally verify their design and implementation. Unfortunately, the common approaches and existing tools to formally establish the correctness of these systems remain hardly applicable to most legacy HPC applications, that are commonly written in Fortran or C/C++, using the MPI standard. This work addresses the problem of automatically detecting at system-level the equality of the application's state. This allows to automatically verify safety and liveness properties on legacy HPC applications. We present how this state equality detection can be achieved without any source code static analysis, but at runtime using memory introspection and classical debugging techniques. We demonstrate the effectiveness of our approach through the exhaustive verification of several programs from the MPICH3 test suite and through the partial termination analysis of some applications from the Competition on Software Verification (SV-COMP).