Malware detection works by using various techniques and tools to scan, monitor, and analyze the system for signs of malware infection. Signature-based detection, for example, compares the files and processes on the system with a database of known malware signatures, which are unique codes or patterns that identify the malware. Tools such as Windows Defender, Malwarebytes, or Kaspersky can be used for this purpose. Behavior-based detection, on the other hand, observes the actions and activities of the system and looks for any abnormal or suspicious behavior that indicates malware infection. Firewalls, intrusion detection systems, or heuristic analysis software such as ZoneAlarm, Snort, or Emsisoft can be used for this type of detection. Finally, sandbox-based detection runs suspicious files or processes in an isolated and controlled environment (sandbox) and then analyzes their behavior and impact on the system. Virtual machines, emulators, or online services such as VirtualBox, QEMU, or VirusTotal can be used for this type of detection.