Malware is developed with the goal of executing unwanted and malicious functions on IT systems. In most cases, it becomes active without the awareness or consent of users. Depending on its form, malware may provide an attacker with extensive communication and control options with an array of different functions. Among other things, it can be specifically used to read passwords, remotely control IT systems, disable protective software, and steal or encrypt data.

Clients are particularly vulnerable to malware. They are operated directly by users and are thus often a gateway for malicious content of any kind. If users visit malicious websites, open e-mails with malicious content from private accounts, or copy malware via local storage media to their clients, malware can spread via the clients into the respective organisation's network. Central protection mechanisms, such as virus protection on a file or e-mail server, can often be bypassed in this way.