How does Windows Defender detect malicious software?

Windows Defender is a built-in security feature of Windows that provides real-time protection against malware and malicious software (malware). It is designed to protect your PCs from threats such as viruses, spyware, rootkits, and other online threats.

Windows Defender runs in the background and is automatically enabled on your system. It uses advanced techniques like signature matching, heuristic scanning, and behavioral analysis to detect and block malicious activity. It has two main components: the engine and the cloud service.

The engine is responsible for scanning incoming files and data streams for known malicious patterns or signatures. It compares these signatures against an ever-growing list of malicious programs stored in its database. If a match is found, the component blocks the program and alerts the user.

The cloud service takes real-time information from Windows Defender users and sends it to Microsoft’s cloud-based services, where it’s analyzed and compared with known malware patterns. If the pattern matches any that are stored in the cloud, the component will alert users of a potential threat and provide additional details about the detected file or program.

Windows Defender also uses machine learning models to detect unknown malware or suspicious programs. It looks at how the program behaves and what processes it’s running. If it detects any suspicious behavior, it can detect the malicious program even if there isn’t a known malicious signature for it.

In addition to relying on signature matching and behavioral analysis, Windows Defender can also detect malicious activity that originates from malicious websites. The component checks web addresses against a regularly updated list of known dangerous websites and blocks access to them if necessary. This helps to keep your devices safe from malicious downloads as well as from phishing scams.

Finally, Windows Defender can scan your devices for vulnerabilities that could be exploited by malicious programs. It looks for outdated software versions and missing patches and then alerts you so that you can update your devices and remain safe from malicious activity.

Overall, Windows Defender is a powerful tool that provides comprehensive protection against malicious software. It has multiple layers of defense that work together to block both known and unknown malware, as well as protect your devices from malicious websites and vulnerable software.