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HIDS stands for host-based intrusion detection system and is an application that monitors a computer or network for suspicious activities. The monitored activities can include external actors` intrusions and also internal misuse of resources or data.

A host intrusion detection system’s job is to look for suspicious activities or unusual patterns that could result in a system breach. Once the HIDS flags an activity for analysis, the security team can understand the kind of threat they`re dealing with and stop it before it causes damage.

The HIDS name derives from the fact that they work on individual host systems: servers, laptops, mobiles, and any other type of endpoint that produces data you can monitor. A host-intrusion detection system also monitors network activity. As opposed to network intrusion detection systems (NIDS) it does it from the perspective of individual hosts. HIDS only uses networks as a source of data to analyze.

How Does HIDS Work?

HIDS is a security solution that alerts you if an anomalous activity takes place in your company’s IT infrastructure. HIDS software works by logging the suspicious activity and reporting it to the administrators managing the devices or networks in question.

When searching the log files, the host intrusion detection system uses certain rules and policies. It will only flag those pointing to events or activities that the rules have determined as IoCs.

IT Admins are the most familiar with the systems they are managing and the operations they are running. So, they should be the ones defining the rules their HIDSs will be using when scanning log files. However, IT Admins can and should also take advantage of the predefined rules already built into the system. These preset rules have been written by security experts in order to find common signs of intrusion.

It’s common knowledge that most applications that are running on devices and networks can and will create log messages of the activities and functions performed while a session is active. You can collect and organize all the data created by yourself. However, doing so will quickly prove a resource-consuming activity, because of the sheer volume of data. To automatize this kind of processes, use an XDR solution that has a DNS security tool incorporated.

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HIDS Detection Methods

Most HIDS solutions use a combination of the following two methods.

Host Intrusion Detections Systems Based on Signatures

This type of intrusion detection system is focusing on searching for a previously known pattern, identity, or a specific intrusion event. Most IDSs are coming from a database that needs constant updates to keep up with known cyber threats. As long as the database is up to date this type of IDS will do a good job.

However, attackers tirelessly generate new malware or add small changes to their attack methods so databases cannot possibly keep up in real-time.

Host Intrusion Detections Systems Based on Anomalies

As opposed to signature-based HIDS, anomaly-based ones rely more on analyzing “trustworthy behavior” and use machine learning techniques to flag malicious behavior. This will translate sometimes into a higher false-positive rate, as the system might also flag legitimate behavior as well.

Anomaly-based IDS is a good option for determining when someone is probing your network before a cyber-attack. The success of this type of IDS also depends on the degree of distribution across the network and the level of training provided by the IT admins.


HIDS is not the only tool that admins have at hand in order to deal with malicious activities. Aside from the host intrusion detection system they also use NIDS – Network Intrusion Detection System.

HIDS looks at particular host-based behaviors at an endpoint level. It includes apps in use, accessed files, and the information stored in the kernel logs.

On the other hand, NIDS examines the data flow between computers, known as network traffic. It monitors the network for unusual activity.

NIDS can identify an attacker before they get to breach the system, while HIDS acts as a second layer of defense. HIDS acts at the endpoint level if the system is breached.

To take a better decision regarding what Intrusion detection system to use, you should also consider the Security Information and Event Management. This is a subsection of computer security services that brings together both NIDS and HIDS solutions. It provides real-time analysis of security alerts generated by applications and network hardware. NIDS & HIDS usually work together and complement each other’s capabilities.

Why Do You Need a Host Intrusion Detection System?

HIDS tools monitor the log files generated by your applications and create a historical record of activities and functions. Therefore, you can quickly identify any anomalies and signs of an intrusion that may have occurred. Additionally, HIDS makes it easier to search or sort the files by application, date, or other metrics.

The key function that makes HIDS a must-have is the detection feature. This feature saves you the need to sort through the log files for unusual behavior once they’re organized and compiled.

Integrating such a powerful tool into your defense structure is a must. However, automatizing data collecting and processing should not be the end of the story. Automatically collecting and analyzing data covers for a great deal of repetitive work, but nowadays tools can do more for your team.

To avoid alert fatigue and fasten response, consider how an Extended Detection and Response (XDR) solution can support the security team. Not only does it offer the possibility to observe all your digital assets at a glance. It also brings different cybersecurity tools, like DNS filtering, under the same umbrella for a more efficient management.

DNS layer security is not something you can afford to overlook in a continuously changing, ransomware attacks abundant threat landscape. As Nabil Nistar, Head of Product Marketing at Heimdal, points out:

Embracing DNS Security is pivotal for modern enterprises, and within our Heimdal XDR platform, it takes center stage. Powered by our cutting-edge AI-driven Predictive Technology, our DNS Security solution stands as the fortified gateway for pre-emptive cybersecurity.

With the potential to detect and thwart threats at both the network and endpoint levels, it’s not just about protection—it’s about staying ahead in the ever-evolving landscape of cyber threats.

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In Conclusion

HIDS software makes the detection process so much easier for administrators and is a time and energy saver of your team`s time. It is definitely one of the structure bones of your cybersecurity toolkit.

HIDS brings benefits of time and energy saving and a boost of precision in detecting threats that managed to enter the system. Choose to use it the smart way, as part of an easy to manage platform to make the most of it.

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Author Profile

Dora Tudor

Cyber Security Enthusiast

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Dora is a digital marketing specialist within Heimdal™ Security. She is a content creator at heart - always curious about technology and passionate about finding out everything there is to know about cybersecurity.


Thanks for the awesome article. Very insightful!

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