Intrusion Detection System (IDS): What is it?

More personal and proprietary data is available online than ever – and many malicious actors want to get this valuable information. Using an intrusion detection system (IDS) is essential to the protection of your network and on-premises devices.

What is an Intrusion Detection System (IDS)?

An intrusion detection system (IDS) is an application that monitors network traffic and searches for known threats and suspicious or malicious activity. The IDS sends alerts to IT and security teams when it detects any security risks and threats.

Most IDS solutions monitor and report suspicious activity and traffic when they detect an anomaly. However, some can go a step further by taking action when it detects anomalous activity, such as blocking malicious or suspicious traffic.

IDS tools typically are software applications that run on organizations’ hardware or as a network security solution. There are also cloud-based IDS solutions that protect organizations’ data, resources, and systems in their cloud deployments and environments.

Why Intrusion Detection Systems are important?

Modern networked business environments require a high level of security to ensure safe and trusted information communication between various organizations. After traditional technologies fail, an intrusion detection system acts as an adaptable safeguard technology for system security. Cyber attacks will only become more sophisticated, so protection technologies must adapt to their threats.

What Are the Types of IDS?

• Network IDS (NIDS): Network intrusion detection systems (NIDS) are set up at a planned point within the network to examine traffic from all devices on the network. It performs an observation of passing traffic on the entire subnet and matches the traffic that is passed on the subnets to the collection of known attacks. Once an attack is identified or abnormal behavior is observed, the alert can be sent to the administrator. An example of a NIDS is installing it on the subnet where firewalls are located to see if someone is trying to crack the firewall.
• Host-Based IDS (HIDS): A host-based IDS is deployed on a particular endpoint and designed to protect it against internal and external threats. Such an IDS may have the ability to monitor network traffic to and from the machine, observe running processes, and inspect the system’s logs. A host-based IDS’ visibility is limited to its host machine, decreasing the available context for decision-making, but has deep visibility into the host computer’s internals.
• Anomaly-based IDS (AIDS): This solution monitors traffic on a network and compares it with a predefined baseline that is considered “normal.” It detects anomalous activity and behavior across the network, including bandwidth, devices, ports, and protocols. An AIDS solution uses machine-learning techniques to build a baseline of normal behavior and establish a corresponding security policy. This ensures businesses can discover new, evolving threats that solutions like SIDS cannot.
• Signature-based IDS (SIDS): Signature-based IDS solutions use fingerprints of known threats to identify them. Once malware or other malicious content has been identified, a signature is generated and added to the list used by the IDS solution to test incoming content. This enables an IDS to achieve a high threat detection rate with no false positives because all alerts are generated based on the detection of known malicious content. However, a signature-based IDS is limited to detecting known threats and is blind to zero-day vulnerabilities.

Benefits of IDS

Intrusion detection systems offer organizations several benefits, starting with the ability to identify security incidents. An IDS can be used to help analyze the quantity and types of attacks. Organizations can use this information to change their security systems or implement more effective controls. An intrusion detection system can also help companies identify bugs or problems with their network device configurations. These metrics can then be used to assess future risks.

Intrusion detection systems can also help enterprises attain regulatory compliance. An IDS gives companies greater visibility across their networks, making it easier to meet security regulations. Additionally, businesses can use their IDS logs as part of the documentation to show they are meeting certain compliance requirements.

Intrusion detection systems can also improve security responses. Since IDS sensors can detect network hosts and devices, they can also be used to inspect data within the network packets, as well as identify the OSes of services being used. Using an IDS to collect this information can be much more efficient than manual censuses of connected systems.

Intrusion Detection System Challenges

While IDS solutions are important tools in monitoring and detecting potential threats, they are not without their challenges. These include:

• False alarms: Also known as false positives, these leave IDS solutions vulnerable to identifying potential threats that are not a true risk to the organization. To avoid this, organizations must configure their IDS to understand what normal looks like, and as a result, what should be considered a malicious activity.
• False negatives: This is a bigger concern, as the IDS solution mistakes an actual security threat for legitimate traffic. An attacker is allowed to pass into the organization’s network, with IT and security teams oblivious to the fact that their systems have been infiltrated.

As the threat landscape evolves and attackers become more sophisticated, IDS solutions should provide false positives rather than false negatives. In other words, it is better to discover a potential threat and prove it to be wrong than for the IDS to mistake attackers for legitimate users. Furthermore, IDS solutions increasingly need to be capable of quickly detecting new threats and signs of malicious behavior.