Hackers and cyber criminals work tirelessly to develop new ways of infiltrating your network and data. No matter how strong your cybersecurity program is, there is always the chance that your network can be accessed by someone looking to steal your sensitive data. Knowing what these network intrusions look like and how to respond to them is a key part of any data protection program.

A network intrusion is any activity on a network that has not been authorized. These intrusions are sometimes theft, sometimes an information-seeking mission, and sometimes just intended to distract you, so you don’t notice other breaches. Intrusions can have devastating consequences, including data theft and loss of IP, and the drain on your time and resources can be severe. By familiarizing yourself with network intrusions you can avoid these consequences and keep your network safe.

Examples of Network Intrusions

Network intrusions can take many forms, but some kinds are more common than others:


Worms are viruses that enter your system via email or messaging and replicate to spread throughout your network. The virus gathers information which it then transmits back to the hackers who sent it.

Trojan Horse

A Trojan horse is similar in execution to a worm, as they are often sent via email; but trojan horses don’t replicate and are therefore a kind of malware. Trojan horses are frequently disguised as benign or even useful programs like anti-virus technology or wifi hotspots, tricking users into clicking on them which then allows hackers backdoor access to your network.

Traffic Flooding

This is a tactic where attackers overwhelm your bandwidth with more network traffic than you ordinarily have. This ties up your resources and allows attackers to hide in plain sight while infiltrating your systems.

Covert CGI

Common Gateway Interface (CGI) is the technology by which servers communicate with users. If your system isn’t adequately protected with authentication requirements, a hacker can alter the code of your CGI, granting his or her access throughout your system.


This method involves targeting a specific network device via multiple pathways. By taking multiple routes the hackers are able to disguise their activities and avoid detection. Note that this method is only possible in networks that accommodate asymmetric routing.

It can sometimes be challenging to spot unusual activity on a network, given how much normal and authorized activity is happening at any given time. A common sign of a network security breach is the activity a hacker might use to disguise their intrusion. For example, intruders might delete access records to hide the fact that they have been in your system, or they might encrypt the data they’ve stolen. If system files are disappearing or appearing without cause, there’s good chance that someone has infiltrated your network.

Some of the clearest indicators of an intrusion happen on individual computers and devices. Slow connection speeds, program malfunctions, and unauthorized password changes or requests can all be signs that your system is compromised. If you or your staff notice any of these activities, you should begin a closer investigation immediately.

Tips for Network Intrusion Detection

Cybercriminals are savvy, and any tool that claims to protect your network can quickly become obsolete. Firewalls and other protective measures are still an important part of information security, but the best consistent defense against a network intrusion is early anomaly detection. The faster you can determine that your system has been accessed, the faster you’ll be able to address any data breaches and prevent further information from being compromised.

An Intrusion Detection System (IDS) can be a helpful addition to your information security plan. These tools regularly monitor network traffic (Network Intrusion Detection System, or NIDS) or host devices (Host Intrusion Detection System, or HIDS), using algorithms and machine learning to detect any anomalies that could be a sign of malicious activity. They do this by scanning your operating system for data packets that differ from your ordinary day-to-day operations. It’s advisable to integrate both host and network intrusion detection systems, as using only one can result in security vulnerabilities.

An IDS can be designed to detect different kinds of attacks, depending on your company’s needs. For example, a Signature-Based IDS will focus on finding “signatures,” or known attack patterns used by hackers. An Anomaly-Based IDS is a broader approach that searches for potential malware attacks. These systems won’t keep hackers out, but they can help you spot a breach before the intruder can fully access your network.

Intrusion Prevention Systems (IPS) go one step further and attempt to block any suspicious activity that’s detected. They are usually used in tandem with an IDS and can be programmed to respond to unusual network behavior with alerts or by blocking unfamiliar IP addresses. There are several kinds of IPS, each focused on specific security concerns. For example, Network Behavior Analysis specifically targets the influx of traffic that often results from denial of service attacks.

ZenGRC Helps Safeguard Businesses From Cyber Threats

Tracking your company’s vulnerabilities can be the hardest part of establishing a successful security program. To create a strong defense, you need to know where your weaknesses lie and where cyber attacks are most likely to occur.

ZenGRC is an integrated software program that allows you to track your company’s risk in real time. By providing a thorough and holistic view of your risk landscape, ZenGRC can help you catch threats before they become liabilities. Schedule a demo today and learn more about how ZenGRC can upgrade your risk management efforts.