This report describes some of the most well known denial of service attacks (DoS-attacks). This will be done in the first part of the report, the second part describes an implementation of a DoS-attack. The main purpose of its first part is to closer examine common DoS-attacks, the purpose of such attacks, the protection methods that can be deployed to mitigate these attacks and the ways that are used to measure these attacks. The second part describes a implementation of a practical attack implemented using HTTP POST requests to overwhelm a web server, so called HTTP POST attack. The attack was carried out using different number of attack nodes, up to the default maximum limit for Apache web server. The attack succeeded after several attempts with different parameters. As a result of the experiments we learnt that a successful HTTP POST attack needs to take between 15% and 100% of the maximum permitted clients to make an impact on the server’s response time. The server that was attacked had no defence mechanism to protect itself against DoS-attacks. One important thing to note is that this attack is carried out in a protected environment so as not to affect the external environment.

The focus of this work is crypto-ransomware; a variant of malware, an analysis of this malware’s network communication, and the identification of means by which it may be detected in the network. The thesis describes the methodology and environment in which the malware’s network communications were studied. The first part of the thesis provides a network traffic analysis of this type of malware with a focus on HTTP and DNS communication, including anomalies that can be observed in the network during this malware’s activity. The thesis also includes a discussion of the user behavior of devices infected by this type of malware. The resulting data was used to identify and describe four detection methods that are able to recognize the malware from its network communication using the HTTP protocol. Finally, a description of several signatures that can be used as indicators of a possible infection by this malware are provided.

The presented work deals with the development of a monitoring system for monitoring the operation of the laboratory. The theoretical part of the work includes information on the safety of operation and work in biological laboratories, measured physical quantities and the principle of their measurement. The monitoring system is built on a compact ESP32-CAM camera and a WeMos D1 development board. The practical part consists of the design and implementation of a given system and the creation of a full-stack application for displaying live input from the laboratory for monitoring measured quantities in real time.