In the last decade, our group has developed a tool called Gorille which implements morphological analysis, roughly speaking control graph comparison of malware. Our first intention was to use it for malware detection, and this works quite well as already presented in [2]. However , morphological analysis outputs a more refine output than 'yes' or 'no'. In the current contribution, we show that it can be used in several ways for retro-engineering. First, we describe a rapid triggering process that enlighten code similarities. Second, we present a function identification mechanism which aim is to reveal some key code in a malware. Finally, we supply a procedure which separate different families of code given some samples. All these tasks are done (almost) automatically seen from a retro-engineering perspective.