This thesis is focused on the security risks that the users are exposed to, while using applications that connect to the Internet. During the research which had been conducted, two Web-Browsers, two Instant Messengers and one File Sharing application have been used in order to generate traffic through the Internet. The purpose of the experiment was to reveal what types of attacks each application was accepting, while it was generating traffic on the Internet. The applications of the same type have been tested together at the same time and each type of application had been tested at different times, for forty hours each. While these applications were running, the traffic that they generated had been captured. According to the analysis from t...