Introduction

Network intrusions are on the rise globally, posing significant threats to organisations of all sizes. As cybercriminals evolve their tactics, the urgency to detect and prevent these attacks has never been greater. The global surge in cyber incidents including data breaches and ransomware attacks - highlights a critical gap in network security and a growing demand for certified cybersecurity professionals who can safeguard sensitive data. With businesses facing increasing risks, the need for advanced network intrusion detection systems and skilled professionals to implement them is paramount.

Overview of Network Intrusion

Network intrusion aims to unlawfully access an organisation’s database with the intent to manipulate, damage, or steal data. These attacks are primarily divided into two types: active and passive.

Active & Passive Attacks

Cyber attackers launch Active attacks on a network to modify, encrypt, and delete data.
On the other hand, a Passive attack is launched without raising an alarm. The hackers intend to simply intrude on a network without altering the company data. This silent intrusion is the smartest technique to prevent the security team from sensing the need for network intrusion detection. This way, the attackers can continue staying in the organisation’s network and accessing the digital assets for months and even years.
Other types of network intrusions are:

Man-in-the-middle attacks

SQL and code injection attacks

Distributed Denial of Service (DDoS) attacks

Insider Threats

How to detect network intrusion?

One of the most practical ways to detect network intrusion is to integrate IDS (Intrusion Detection System) in the organisation’s network. Intrusion Detection Systems (IDS) distinguish between normal network traffic and suspicious activities in the network. IDS are mainly divided into 5 types:

• Host Intrusion Detection System: This solution runs on network hosts or standalone devices, periodically capturing snapshots of system files and comparing them with prior versions. Any discrepancies, such as changes or deletions, prompt an alert to notify the administrator for detailed inspection.
• Network Intrusion Detection System: They are strategically placed across the network for traffic monitoring of the devices connected to a network. As soon as the system senses any threats, it alerts the administrators. The system accomplishes the following regular security tasks:
  i) Monitoring systems setups and settings ii) Analysing users' behaviour iii) Identifying malicious activities iv) Scanning sophisticated intrusion techniques v) System file comparisons to prevent malware signatures in a network
• Protocol-based Intrusion Detection System (PIDS): This system monitors and analyses the protocol between a user's device and servers. It is usually installed on the server's front end to secure web servers.
• Application Protocol-based Intrusion Detection System (APIDS): This intrusion detection system is deployed within a cluster of computers. It detects intrusion by monitoring and analysing application-specific protocol traffic.
• Hybrid Intrusion Detection System: These detection systems blend host-based and network-based approaches to create a unified view of system activities and enhance security effectiveness beyond traditional detection methods.

How to prevent network intrusion?

Network intrusion prevention encompasses some of the best practices as follows:

• Integration of a next-gen firewall enhances network security by detecting and blocking sophisticated threats in real time. It enables deep packet inspection, application awareness, and automated threat intelligence.
• Network segmentation isolates a network into mini segments. It reduces the attack surface and limits the lateral movement of threats, thereby enhancing intrusion prevention.
• Network segregation is a process that separates critical systems from less secure networks. It helps to create barriers that prevent unauthorised access and contain potential intrusions, strengthening overall network security.
• Network Address Translation (NAT) helps prevent network intrusions by hiding internal IP addresses. The technique makes it harder for attackers to directly target individual devices. It acts as a barrier, filtering incoming traffic and allowing only established connections to pass through.

Conclusion

Network intrusion poses significant threats to organisations, emphasising the need for robust security measures. This has also led to a rising demand for pentesters who are skilled in intrusion detection in network security and closing the security gaps.
Join our Penetration testing course online that provides essential skills to identify vulnerabilities and simulate real-world attacks, helping cybersecurity professionals strengthen defenses. By mastering these techniques, individuals can effectively protect networks against potential intrusions and safeguard critical data assets.