Kauzalita výskytu různých druhů malwaru v potenciálně nebezpečných skupinách internetových stránek

This bachelor thesis deals with the issue of Internet danger, namely, what kinds of malware are present, in what groups of pages and how to protect against them. This work has three main objec-tives. The first objective is to compare the best-known antivirus products in the Czech Republic, the second objective is to define potentially dangerous groups of websites, analysis of occurrence of malware and determine the causality of these viruses. The final goal is to define tips and recom-mendations on how to avoid malware in each group and then build decision table, which will rec-ommend the best antivirus products for every group.The theoretical part explains the concept of malware and its causes and reasons of creation. It also describes the development of malware from the 1970s to the present. The following section dis-cusses how malware is divided into basic types. It also describes how malware can be analyzed using a variety of methods and how to detect malware. Another part of the theoretical work is de-voted to the prevention and protection against malware. The last part deals with the difference and classification of malware.The practical part follows the theoretical part. The first part focuses on comparing the five most popular antivirus products in the Czech Republic, it is compared according to defined criteria. The next part contains defining potentially dangerous groups of websites, then analyze the occurrence of malware in these groups with tool VirusTotal and determining sub-causal occurrence. The pe-nultimate part of the practical part is primarily devoted to defining tips and recommendations, how to avoid malware in each group. And the last part of the bachelor thesis is based on all the previous parts of the practical part and there is made a decision table.