Attacks that make headlines, like the Colonial Pipeline hack that forced the closure of a significant US pipeline for more than a week, show their capacity to cause enormous damage. What Is an Intrusion Detection System? Organizations paid an estimated $350 million in ransomware attacks in the US alone in 2020. For every significant breach, hundreds of attacks completely destroy smaller companies and their clients.

To fully defend a network from an assault, firewalls, and anti-malware software are insufficient. An intrusion detection system (IDS), which identifies suspect traffic once it has passed the firewall and entered the network, should be a part of any comprehensive security plan.

An introduction to intrusion detection systems and their function in network security is provided in this article. Continue reading to find out how these systems function and why they are essential for preventing costly downtime and data breaches.

What Is an Intrusion Detection System (IDS)?

A software or device called an intrusion detection system (IDS) keeps track of all network traffic, both inbound and outbound continuously scans the data for deviations from the norm and notifies the administrator of any suspicious activity. The threat is then eliminated when an administrator checks alarms.

An IDS, for instance, might examine the information carried by network traffic to check for the presence of known malware or other dangerous content. If it finds this kind of threat, it alerts your security team so they can look into it and take the appropriate action. To stop an attack from taking over the system, your team must respond immediately after receiving the alarm.

These systems frequently use a switching port analyzer (SPAN) or test-access port (TAP) to examine a copy of the inline data traffic in order to make sure that an IDS doesn’t affect network performance. They do not, however, prevent threats from entering the network as intrusion prevention systems do.

What Is an Intrusion Detection System? Whether an IDS program is installed or a physical device is put up, the system can:

• Analyze the patterns of attacks in network packets.
• Observe how users behave.
• Determine any unusual traffic patterns.
• Make sure that user and system behavior does not violate security guidelines.

The security team can additionally benefit from the information from an intrusion detection system by:

1. Check the network for weaknesses and incorrect setups.
2. Analyze the files’ and systems’ integrity.
3. Improve the controls and incident response processes.
4. Analyze the number and kind of online threats that are affecting the network.

Aside from the advantages of cybersecurity, an IDS also aids in regularity compliance. Improved logging and increased network visibility guarantee that network operations comply with all applicable laws.

Goals of Intrusion Detection Systems

Modern cyber dangers cannot be adequately protected by a firewall alone. Malicious content is frequently distributed utilizing legitimate types of transmission, such as email or web traffic. An IDS gives the capacity to examine the information in these communications and find any potential malware.

An IDS’s principal objective is to find abnormalities before hackers succeed in their mission. When a threat is identified, the IDS notifies the IT team and provides them with the following information about the risk:

• The intrusion’s origin IP address.
• Addresses to the target and victim.
• the kind of danger.

An intrusion detection system’s observation of intruders and identification of them is a secondary objective:

1. What assets an attacker attempts to access.
2. How hackers attempt to get around security measures.
3. what kinds of cyberattacks the invaders launch.

This information can be used to strengthen the network security strategy by the company’s security operations center (SOC) and analysts.

An intrusion detection system’s two main purposes are anomaly detection and reporting. Some detection systems can, however, take action in response to malicious behavior, such as immediately blocking an IP address or preventing access to private data. Intrusion prevention systems are those with these reaction capabilities (IPSs).

What Is the Process of Intrusion Detection Systems?

All network traffic to and from all devices is observed by an IDS. The system, which serves as a secondary filter for malicious packets behind a firewall, mainly scans for two suspicious indicators:

• Signs of well-known attacks.
• Deviations from routine behavior.
• What Is an Intrusion Detection System?

What Is an Intrusion Detection System? In order to identify threats, an intrusion detection system often uses pattern correlation. Using this technique, an IDS can examine network packets against a database of known cyberattack signatures.

The most typical assaults that a pattern correlation-based IDS may detect include:

1. Malware (worms, ransomware, trojans, viruses, bots, etc). (worms, ransomware, trojans, viruses, bots, etc.).
2. Assaults that send packets to the network in order to collect information on open or closed ports, allowed traffic kinds, running hosts, and software versions.
3. Asymmetric routing uses separate entry and exit routes to send a malicious packet and get around security measures
4. Buffer overflow attacks that substitute malicious executable files for the database content.
5. Assaults on a certain protocol that is protocol-specific (ICMP, TCP, ARP, etc.).
6. Network overloading traffic breaches like DDoS attacks cause the network to overflow.

The system flags the problem and sounds the alarm as soon as an IDS detects an anomaly. The alarm could be as straightforward as a notation in an audit log or as critical as a communication to an IT administrator. The team then investigates the issue and determines its primary cause.

What Are the Types of Intrusion Detection Systems?

Based on where the security team installs them, there are two primary types of IDSes:

1. System for detecting network intrusions (NIDS).
2. The mechanism for detecting host intrusions (HIDS).

We may also distinguish between two groups based on how an intrusion detection system picks up on suspicious activity:

1. An intrusion detection system based on signatures (SIDS).
2. A system for detecting intrusions based on anomalies (AIDS).

You can employ either a HIDS or NIDS, or you can rely on both of the basic IDS kinds, depending on your use case and budget. As many teams set up a hybrid system with SIDS and AIDS capabilities, the same is true of detection models.

You need to comprehend the variations among IDS types and how they work in concert with one another before you decide on an approach. Let’s examine each of the four primary IDS kinds, their benefits and drawbacks, and appropriate usage scenarios.

Network Intrusion Detection System (NIDS)

What Is an Intrusion Detection System? What Is an Intrusion Detection System? A network-based intrusion detection system tracks and examines every network device traffic. Typically, at data chokepoints, a NIDS operates from a strategic location (or points, if you deploy several detection systems) within the network.

Benefits of a NIDS

1. Protects the network as a whole with IDS.
2. An enterprise-sized network can be monitored by a few carefully placed NIDSes.
3. A non-active device that doesn’t reduce network performance or availability.
4. Quite simple to conceal from burglars and safeguard.
5. Includes areas of networks where traffic is most at risk.

Drawbacks of a NIDS:

1. Costly to set up.
2. A NIDS system may experience low specificity and the sporadic occurrence of an undetected breach if it is required to monitor a large or active network.
3. Threat detection in encrypted traffic can be challenging.
4. Usually not the best match for switch-based networks.

System for detecting host intrusions (HIDS)

A HIDS monitors network traffic and system logs to and from a single device while operating from a defined endpoint.

Regular snapshots—file sets that record the current state of the entire system—are the foundation of this sort of IDS security. The IDS looks for missing or changed files or settings when the system takes a snapshot and compares it to the prior state.

Benefits of HIDS

1. provides extensive insight into the host device and its operations (changes to the configuration, permissions, files, registry, etc.).
2. a strong backup line of defense against a malicious packet that a NIDS missed.
3. Excellent at identifying packets coming from inside the company, like unwanted file changes from a system console.
4. effective at finding and preventing breaches in software integrity.
5. Due to fewer packets, it is more effective than a NIDS at decrypting encrypted communication.
6. Much less expensive than putting up a NIDS

The drawback of HIDS

1. limited visibility because only one device is monitored by the system.
2. less context is accessible for decision-making.
3. Large businesses find it challenging to maintain because a team needs to configure and handle information for each host.
4. a NIDS is less visible to attackers.
5. Not good at identifying network scans or other attacks that target the entire network for surveillance.

System for detecting intrusions based on signatures (SIDS)

What Is an Intrusion Detection System? A SIDS keeps track of packets as they move through a network and evaluates them against a database of acknowledged attack signatures or characteristics. This prevalent IDS security type searches for particular patterns, like byte or instruction sequences.

Benefits of SIDS

• Effective against intruders utilizing recognized attack signatures.
• Useful for identifying low-tech assault tries.
• Effective at keeping track of network traffic coming in.
• Can effectively handle a lot of network traffic.

Cons of SIDS

1. Without a precise signature in the threat database, a breach cannot be identified.
2. A clever hacker can change an attack to avoid matching recognized signatures, for example, by changing lowercase characters to uppercase or a symbol to its character code.
3. Need frequent threat database updates to keep the system current with emerging threats.

A system that detects intrusions based on anomalies (AIDS)

AIDS tracks current network activity and examines patterns in comparison to a reference point. Instead of focusing on specific data patterns, it extends beyond the attack signature concept to identify malicious behavior patterns.

With regard to bandwidth, protocols, ports, and device utilization, this kind of IDS establishes a baseline of expected system behavior (trust model) using machine learning. The system can then assess any novel activity against validated trust models to find undiscovered assaults that a signature-based IDS is unable to recognize.

What Is an Intrusion Detection System? For instance, the attempt to access the website’s backend by someone in the sales department may not be a sign of a SIDS. A person attempting to access a sensitive system for the first time, however, is a reason for investigation for an anomaly-based setup.

The advantages of AIDS

1. can spot indicators of unique risks and undiscovered attack kinds.
2. relies on AI and machine learning to build a model of reliable behavior.

Drawbacks of AIDS

1. Difficult to manage
2. More processing power is needed than with a signature-based IDS.
3. Alarm volume can overwhelm administrators.

Conclusion

For network security to remain at acceptable levels, a high-quality IDS (or IPS) is essential. An IDS can miss some possible risks since it only identifies threats. Therefore, preventing attacks and defending your company against them is insufficient on its own.

What Is an Intrusion Detection System? Instead, an IDS is a component of your overall security plan. You need to make sure your staff, who are your first line of defense, know how to protect your company, information, and assets in addition to having the appropriate security technologies in place.

An efficient program for raising cybersecurity awareness is the first line of defense. As a result, they’ll be more assured in their capacity to react and respond to them, as well as minimize risks to your business and your customers.