Anti-virus programs scan the media and memory of a computer or smartphone for known malware. If something suspicious is found during the scan, the program reports this discovery to the user or removes the malware automatically, depending on the settings.
Such protection programs are part of the basic equipment to increase the security of a device. In this way, malware can be detected and countermeasures taken, no matter how they got onto the device.
In addition to conventional signature-based virus scanners, there are also other types. Since they react too late with ransomware malware, for example, pattern-based scanners – i.e. those that can detect malicious behaviour – were developed.