How does an IDS detect intrusions?

IDS can monitor the signatures of all inbound and outbound network traffic and compare them against a database of signatures of malicious threats. If a new threat remains undetected, the database of signatures is updated with the signature of the new threat so that the threat can be detected in the future. This method of intrusion detection is called signature-based intrusion detection.

IDS can also monitor system behavior and create a baseline of allowed activities. If any suspicious activities like modification of system files are found, it can alert the system administrator. This method of intrusion detection is called anomaly-based intrusion detection.

What are the limitations of an IDS?

There are a couple of limitations to IDS.

  • The effectiveness of an IDS can be limited by noises like software bugs, corrupt DNS data, etc., and IDS can create false alarms.
  • An outdated database of signatures can make the IDS significantly vulnerable.
  • In the time lag between the detection of new undetected threats and updating the database of threats, the IDS can be vulnerable to the new threats.
  • If an intruder breaks the authentication mechanism, the IDS cannot detect that attack.
  • Encrypted packets are not processed by IDS. So they can remain undetected and pose a threat.

So, be aware of various intrusions, and stay safe and secure. Interested readers who want to know more about how different malware and cyberattacks work and how we can prevent them may want to refer to the book “A Guide To Cyber Security.”

Security Fundamentals Practice Tests

The Security Fundamentals Practice Tests test one’s fundamental knowledge of cyber security. The practice tests are good for those who are preparing for various certification exams like the CCNA, CCNP, or CompTIA. They are also good for students and IT/security professionals who want to improve their understanding of cybersecurity.

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Amrita Mitra

Author

Ms. Amrita Mitra is an author, who has authored the books “Cryptography And Public Key Infrastructure“, “Web Application Vulnerabilities And Prevention“, “A Guide To Cyber Security” and “Phishing: Detection, Analysis And Prevention“. She is also the founder of Asigosec Technologies, the company that owns The Security Buddy.

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