The actor behind Bisonal is clearly motivated and has an interest in Russian, Korean and Japanese victims. The development of Bisonal has been active for more than a decade. We have observed the code evolving with the different publications but also with the evolution of Microsoft Windows. However, specific functions are still used today, many years after the original implementation of the Bional malware. Even if Bisonal could be considered as simple with less than 30 functions, it has spent its life targeting sensitive entities in both the public and private sectors. With this investigation and the analysis of this decade of activity, we hope to force this actor to innovate by providing a better understanding of his arsenal and more specifically how Bisonal works