The authors demonstrate a working proof-of-concept of reweaponization by replacing payload in an up-to-date, real world APT malware sample (discovered year 2017, contains 3 0days), while leaving the exploitation part intact. Furthermore, two separate paths for malware reweaponization are shown:replacing whole payloadreplacing C&C domainsThe sample analysed consists of several layers, that need to be thoroughly analysed and repackaged for successful binary editing:MS office documentembedded postscript imagepacked postscriptshellcodepacked shellcodedropper executablepayload executableC&C domains Authors will describe the analysis process step-by-step, the binary modification and reverse process to get hold of modified working sample.Malware reweaponization is not novel, it has recently been mentioned in public discussions, and there is evidence of this technique being used for several years by intelligence agencies. The purpose of our proof-of-concept is to demonstrate the ease with which reweaponization can be achieved.The value of this work is in understanding the cyber threat landscape as it changes. We expect that malware reuse will gain popularity creating additional workload for CSIRT teams and will furthermore complicate the attribution of cyber attacks.Traditionally, attribution in cyberspace is based on the Tactics-Techniques-Procedures triad, with tools being the category most relied upon. Expanded use of malware reweaponization would render tool-based attribution fairly ineffective, providing a near-perfect false flag cyber operation.Note: The strict scientific guidelines require to reveal enough information to make our experiments repeatable. Unfortunately this also means any competent reader could make their own cyber weapon, a clearly undesireable consequence. Thus we do not provide malware sample and detailed instructions (exact byte offsets etc). In authors opinion this decision in no way affects our contribution, as the main goal of technical section is to demonstrate that malware reweaponization is relatively easy.