Intrusion Detection System (IDS) Examples: 3 Systems to Know

By Tibor Moes / Updated: June 2023

Intrusion Detection System (IDS) Examples: 3 Worst Attacks

Intrusion Detection System (IDS) Examples

Imagine you’re a homeowner and you’ve just installed a cutting-edge home security system. This system doesn’t just alert you when someone breaks in; it keeps a keen eye on the yard, notes any unusual activities, and lets you know if someone is trying to scale the fence. In the cyber world, Intrusion Detection Systems (IDS) work in a similar way, keeping our virtual homes – our networks – safe and secure.


An Intrusion Detection System (IDS) is like a digital watchdog. It monitors network traffic and alerts us to suspicious or malicious activity, safeguarding our digital spaces from cyber threats.

Example 1 – The Bro (Zeek) Network Security Monitor (1998): This powerful open-source software provided detailed traffic analysis, focusing on network protocols to spot suspicious behavior. Born in the labs of Lawrence Berkeley National Laboratory, it quickly gained popularity for its scriptability and high-speed performance.

Example 2 – Snort (1998): Developed by Sourcefire’s founder Martin Roesch, Snort is a free and open-source IDS that became a household name in cybersecurity. It excels in packet logging and real-time traffic analysis, providing customizable rules for detecting intrusions.

Example 3 – Suricata (2009): Sponsored by the Open Information Security Foundation (OISF), Suricata is a high-performance IDS, Intrusion Prevention System (IPS), and Network Security Monitoring (NSM) engine. It’s known for multi-threading capabilities, automatic protocol detection, and its ability to use existing rulesets from Snort.

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Intrusion Detection System (IDS) Examples In-Depth

The Bro (now Zeek) Network Security Monitor (1998)

When you’re trying to ensure the security of your home, you would ideally want a system that doesn’t just bark when an intruder is at the door. You’d prefer it to be observant, detecting if someone is lurking around your property, and alerting you of potential threats beforehand. In the world of network security, one such system that has been working as an intelligent guardian since 1998 is the Bro Network Security Monitor, now called Zeek.

Zeek, like an expert detective, doesn’t just look for the obvious signs of trouble. Instead, it’s known for meticulously inspecting every bit of data that comes and goes on a network. Imagine it as the keen-eyed security guard, watching the CCTV screens, who can tell that something’s off simply because a car parked in the lot has its lights on at an unusual hour. Zeek operates similarly, keeping a vigilant eye on network protocols, user behaviors, and patterns. If something looks out of the ordinary, Zeek makes a note of it.

One of the main reasons for Zeek’s popularity is its versatility. Picture a Swiss Army knife with a tool for every need. Zeek has an extensive, customizable scripting language that allows it to analyze network activities in real-time. This enables it to adapt to different environments, making it a one-size-fits-all solution. It’s a bit like having a security system that you can tweak to pay extra attention to certain windows, doors, or even specific times of the day.

Another standout feature of Zeek is its focus on high-speed performance. Picture a top-tier athlete, swift and agile, covering every inch of the field in no time. Just like that athlete, Zeek handles vast networks efficiently, even those with high bandwidths. This means it can manage bigger digital estates without slowing down the system, making it the choice of large-scale organizations and research institutions.

To summarize, the Bro Network Security Monitor, now known as Zeek, is like a dynamic, intelligent, and vigilant security guard for your network. Its keen eye for details, combined with its adaptability and efficiency, makes it an invaluable asset in the quest for network security. Just like the security guard who knows the daily ins and outs and quickly recognizes when something’s amiss, Zeek keeps watch over our virtual homes and alerts us if something unusual is happening. It’s a real hero, silently working to keep our networks safe and secure.

Snort (1998)

Imagine being in a bustling market where hundreds of people are chatting, negotiating, and bartering. Suddenly, you hear a sharp whistle – the unmistakable sound of a referee’s call. All heads turn to see what happened. This ability to cut through the noise and alert everyone to a rule violation is what the Snort Intrusion Detection System, launched in 1998, brings to the world of network security.

Just like a referee in a sports game, Snort watches the flow of data on a network with a discerning eye. It is looking for foul play, or in the case of a network, malicious activities. If it spots something suspicious, it doesn’t hesitate to “blow the whistle” and alert the system administrators about the potential threat.

One of Snort’s standout features is its robust traffic analysis and packet logging capabilities. Picture an airport security officer thoroughly scanning luggage for any potentially hazardous items. Similarly, Snort examines each data packet as it moves across the network, ensuring no harmful content slips through unnoticed. It’s this thorough inspection that has made Snort a reliable watchdog in the digital world.

Now, just as every sport has its rulebook, Snort has a set of predefined rules to guide its detection process. The truly great thing about Snort, though, is that its rules aren’t fixed and rigid. Instead, they are customizable, allowing users to tailor Snort to their specific needs. Imagine being able to tweak the rulebook slightly, so the referee knows to keep an extra eye on certain players who have a history of bending the rules. That’s the kind of flexibility Snort offers, allowing you to highlight areas of concern that are unique to your network.

Despite being a highly technical tool, Snort has built a reputation for its user-friendly nature. It’s like having a top-level referee who not only excels at enforcing the rules but also takes the time to explain his calls in a way the spectators can understand. Snort’s alerts are clear and easy to comprehend, ensuring users aren’t left scratching their heads when an alert is sounded.

In summary, Snort is like the vigilant referee of your network’s soccer match. Always alert, always watching, and ready to blow the whistle the moment foul play is detected. Its ability to analyze data traffic in detail, coupled with its user-friendly approach, makes Snort an indispensable tool in the world of network security. It’s been standing guard over our networks for decades, keeping us safe from cyber threats and ensuring the game is played fairly.

Suricata (2009)

Imagine you’re at a bustling train station with trains coming and going, passengers rushing about, and a ton of activities happening all at once. Now, imagine you’re the station master tasked with ensuring everything runs smoothly. You need to be incredibly observant, able to multitask, and quick on your feet. That’s Suricata for you, in the world of network security.

Introduced in 2009 by the Open Information Security Foundation (OISF), Suricata is like a super-efficient station master, managing the intricate network of data traffic. It’s known for its high-performance capability, making it a go-to choice for larger networks, much like a busy metropolitan train station.

One standout feature of Suricata is its multi-threading capability. Think of it like having several pairs of eyes and ears, each dedicated to observing a specific part of the train station. This ability allows Suricata to monitor multiple data streams simultaneously, ensuring that no suspicious activity slips past unnoticed, no matter how busy the network traffic gets.

A key advantage of Suricata is its ability to automatically detect network protocols. This is like a station master who can instantly tell which train is arriving just by the sound of its whistle. This feature means that Suricata can identify and handle various network protocols, which enhances its versatility and adaptability.

But Suricata doesn’t stop there. It not only detects potential threats but can also take preemptive action to prevent an attack, thanks to its Intrusion Prevention System (IPS) capability. Imagine a station master who doesn’t just notify the authorities when a threat is detected but also takes steps to prevent any harm from occurring. That’s Suricata for you – always a step ahead when it comes to network security.

What’s more, Suricata is designed to be compatible with rulesets from Snort, one of its older counterparts. This means it can apply the knowledge and experience gleaned from years of Snort’s operations, just like a new station master who follows established protocols to ensure smooth operations.

In summary, Suricata is like the efficient, multi-tasking station master of your network, overseeing the constant traffic flow and ensuring everything runs smoothly. Its multi-threading capability, automatic protocol detection, and proactive defense system make it a strong pillar in network security. Suricata is the vigilant guard that not only alerts you to potential threats but also takes action to prevent them, securing your network effectively and efficiently.


Just like homeowners invest in security systems to protect their property, or sports officials monitor games to keep play fair, our computer networks need vigilant guardians to protect them from cyber threats. Intrusion Detection Systems (IDS), like Zeek (formerly Bro), Snort, and Suricata, serve as these crucial sentinels, each bringing unique strengths to the table. Zeek’s detail-oriented analysis, Snort’s user-friendly approach, and Suricata’s multitasking prowess all contribute to securing our networks, much like a security guard, a referee, and a station master each contribute to their respective fields. As cyber threats continue to evolve, so too will these systems, always adapting to keep us one step ahead in the ever-important game of network security.

How to stay safe online:

  • Practice Strong Password Hygiene: Use a unique and complex password for each account. A password manager can help generate and store them. In addition, enable two-factor authentication (2FA) whenever available.
  • Invest in Your Safety: Buying the best antivirus for Windows 11 is key for your online security. A high-quality antivirus like Norton, McAfee, or Bitdefender will safeguard your PC from various online threats, including malware, ransomware, and spyware.
  • Be Wary of Phishing Attempts: Be cautious when receiving suspicious communications that ask for personal information. Legitimate businesses will never ask for sensitive details via email or text. Before clicking on any links, ensure the sender's authenticity.
  • Stay Informed. We cover a wide range of cybersecurity topics on our blog. And there are several credible sources offering threat reports and recommendations, such as NIST, CISA, FBI, ENISA, Symantec, Verizon, Cisco, Crowdstrike, and many more.

Happy surfing!

Frequently Asked Questions

Below are the most frequently asked questions.

What's the main difference between an IDS like Snort and an IPS like Suricata?

An Intrusion Detection System (IDS) like Snort primarily monitors network traffic and alerts you to any suspicious activities. On the other hand, an Intrusion Prevention System (IPS) like Suricata goes one step further. It not only detects potential threats but also takes actions to prevent them, hence the name ‘prevention’ system.

Why would a network choose to use Zeek over other IDS systems

Zeek (formerly known as Bro) is known for its powerful network analysis capabilities. It can observe and make sense of what’s happening on the network at a very granular level. Moreover, its scripting language is highly flexible and adaptable, making it a solid choice for environments with specific or unique requirements. Its high-speed performance also makes it ideal for large-scale networks.

Can Snort and Suricata be used together on the same network?

Yes, Snort and Suricata can be used together on the same network. Each has its unique strengths and they can complement each other well. For instance, Snort’s ease of use and powerful rule-based detection can work hand-in-hand with Suricata’s multi-threading capability and proactive prevention features. However, deploying and managing both might require more resources and technical expertise.

Author: Tibor Moes

Author: Tibor Moes

Founder & Chief Editor at SoftwareLab

Tibor is a Dutch engineer and entrepreneur. He has tested security software since 2014.

Over the years, he has tested most of the best antivirus software for Windows, Mac, Android, and iOS, as well as many VPN providers.

He uses Norton to protect his devices, CyberGhost for his privacy, and Dashlane for his passwords.

This website is hosted on a Digital Ocean server via Cloudways and is built with DIVI on WordPress.

You can find him on LinkedIn or contact him here.

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