This bachelor thesis adresses present day topic of broad interest, the topic of malware. This term stands for malicous software as viruses, worms, trojans, spyware etc. Simply put a software with intent to do harm to the users of computers or mobile devices, to their steal information or gain access to their private computer systems. This thesis is divided into several chapters. First few of them are theoretical. First one describes malware in general. It defines what malware is and divides it into categories. Second chapter introduces a discipline of malware analysis. A discipline where malware, its components and behaviour is analysed in laboratory environment. This chapter contains general description of malware analysis, categories in w...