How To Detect And Prevent Network Intrusion by Farwa Sajjad

A network intrusion is known as any vigorous or unauthorized activity that takes place on a digital network. All these illegal activities always risk the security of systems and their data. At present, the online brands and companies are the subjects of these attacks. However, to combat this, organizations must have a cybersecurity team actively working in place. It will help organizations have an in-depth understanding of how these intrusions work and influence the detection systems.

The network intrusion detection (IDS) and prevention (IPS) systems attempt to find the unauthorized access on an organization’s network by determining the traffic on the net for signs of some malicious activity. They are placed at the start and ending points of the system to identify abnormal traffic.

To further aid our readers in this regard, we’ve compiled this article for them. But, before we get into the main topic, let’s first discuss the attacks that result due to network intrusion.

Types of Attack Techniques

In several cases of network intrusion, the attack involves either flooding or overloading of the network to attack it from a vulnerable point. Later, the information is inserted into the net to spread and gain access from inside. Hackers can take different approaches when trying to enter a system. Now, let’s discuss some of the most widespread types of network intrusion attacks.              

1. Multi-Routing

It is also known as asymmetric routing. In this method, the entire idea is to use more than one route to target a particular network. As a result, it allows hackers to escape the detection process by having a significant portion of questionable packets to avoid intrusion sensors in some parts of the network. But, interfaces that are not adequately configured for multi-routing are not prone to this technique.

2. Buffer Overflow Attacks

This method attempts to overwrite individual sections of a computer’s memory within a network by replacing standard data in those memory locations with a string of commands that can later be used as part of the attack. However, this method becomes challenging to accomplish if the network engineer installs boundary checking logic that detects executable codes or long malicious URL strings before it can be written to the buffer.

3. Protocol-Specific Attacks

Devices are bound to follow particular rules and procedures when performing network activities. The protocols like IP, ICMP, ARP, and other several application protocols can leave loopholes for attacks. It can happen in the form of a protocol impersonation, which is also referred to as spoofing. This technique allows hackers to access data they wouldn’t normally have access to or even damage and destroy the targeted devices on a network.

4. Traffic Flooding

Another method of network intrusion is the creation of traffic loads that are too huge for systems to adequately screen. It would then encourage confusion and congestion within the network environment. As a result, hackers get a room where they can execute an undetected attack.

5. Trojan horse Malware

Although all such programs appear to look harmless and do not replicate like a worm or a virus, they can create a network backdoor that provides attackers free access to networks and any available data. Moreover, Trojan malware can also attack systems from online repositories that mainly include peer-to-peer file exchanges.

6. Worms

Worms are the most accessible network intrusion systems, which are considered the most damaging. A worm is an individual computer virus that spreads through email attachments, also known as phishing attacks or instant messaging. The virus ends up using massive amounts of network resources and frustrating authorized activity. Some worms also actively seek out specific types of sensitive information, like financial information or other personal data relating to social security numbers. These attackers then communicate the data to invaders waiting outside the network.

What is an Intrusion Detection System (IDS)?

It is a system that surveys a network for malicious activities and issues a warning when it uncovers any such action. Any threat is directly reported to the administrator. Moreover, this system consolidates outputs from various sources and filters malicious activities from false alerts.

IDS observes networks for suspicious, malicious activity; they also look out for false alerts. It means that organizations need to set up intrusion detection systems to detect what regular traffic on the network looks like when compared to malicious activity. There are two kinds of intrusion detection system, described below:

1. Host Intrusion Detection System

This system runs on self-standing devices or hosts on the network. It takes a snapshot of the existing system files and matches it with the previous pictures. In the same way, if the analytical system files are altered or deleted, it sends a warning to the administrator for investigation.

2. Network Intrusion Detection System

They are placed at strategic points within the network to determine traffic from all devices present on the net. Mainly, it performs an analysis of passing traffic on the entire subnet and matches the traffic moved on the subnet to the collection of the known attacks. Upon detecting an attack or sensing the abnormal behavior, it sends an alert to the administrator.

An IDS is a hardware device or software application that uses known intrusion signatures to identify and evaluate both inbound and outbound network traffic for certain abnormal activities. It is primarily done through the following ways:

  • Monitoring system settings and configurations
  • Tracking user behavior to recognize malicious intent
  • Scanning processes that identify signs of harmful patterns
  • System file comparisons against malware signatures

With identifying a security policy violation, virus or configuration error, IDS can boost a criminal user off the network and direct an alert to security staff. Despite these benefits, including in-depth network traffic analysis and attack detection, the IDS has inherent drawbacks. It uses previously known intrusion signatures to locate attacks; the newly discovered threats remain undetected. Moreover, an IDS is capable of detecting ongoing attacks, not the incoming assaults. To block all these attacks, the need for intrusion prevention systems is vital.

What is an Intrusion Prevention System (IPS)?

Intrusion prevention systems are the network security appliances that monitor network or system activities for malicious activity. The fundamental functions of the IPS are to identify malicious activity, collect information regarding this activity, report it, and also attempt to block it.

They are known as the supplements to Intrusion Detection System because both the IDS and IPS monitor the network traffic as well as system activities for malicious activity. IPS can take proactive actions like sending a warning, reorganizing a connection, and blocking the traffic from the hostile IP address.

An IPS foils an IDS configuration by proactively inspecting a system’s incoming traffic to clear the malicious requests. A typical IPS structure uses web application firewalls and traffic cleaning solutions to secure the applications.

An IPS prevents the attacks by dropping the malicious packets, hindering the offending IPs, and warning the security personnel about any possible threats. Such a system uses a pre-existing database for signature recognition that can be programmed to detect attacks based on traffic and behavioral anomalies.

While being effective at blocking the known attack vectors, some IPS systems do come with limitations, mostly caused by an overreliance on predefined rules, making them vulnerable to false positives.

Types of Intrusion Prevention System

There are four subtypes of intrusion prevention system, briefly described as follows:

1. Network Behavior Analysis

It carefully monitors the network traffic to detect threats that generate irregular traffic flows like DDoS attacks, which is a particular type of malware.

2. Network-Based Intrusion Prevention System

It carefully scans the entire network for irregular traffic protocol analysis.

3. Host-Based Intrusion Prevention System

They are the installed software packages set up to monitor a single host for suspicious activity by determining the events happening within the host.

4. Wireless Intrusion Prevention System

It monitors the wireless networks for any suspicious activity by examining the wireless networking protocols. 

We hope that we’ve made clear to our readers network intrusion and how to detect and prevent it. With that said, all we can say is stay protected!

About the Author:


A freelancer, passionate journalist, and cybersecurity blogger. Likes to write about AI, Cybersecurity, Big data, and internet privacy issues. 
January 16, 2020

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