Among the most popular attack tactics are phishing emails, which to the untrained eye often look like an official email, e.g. from a bank or an online shop. In these cases, victims often disclose their user data and thus make themselves vulnerable. No less dangerous are the numerous different types of malwares that can infect an IT infra-structure. This malicious software takes the form of Trojans, botnets, worms, viruses, spyware, adware, or ransomware. No matter what form they take, they are never up to no good: they spy on sensitive data, sabotage important work processes, take control of a single end device or an entire network, or flood it with unwanted advertising. Ran-somware is an extremely nefarious form of malware because it can lock up essential data, computers, or entire network areas for normal users so that the responsible hackers demand a ransom for their release. For sufficient and successful protection against these criminal machinations, common software alone is not enough. At this point, only the defence strategies of established cybersecurity specialists and sensitisa-tion and education in cybersecurity for all employees can lead to a successful defence against the various threats.