What Is a Zero Day Attack


Do you remember the story in Greek mythology about the Trojan horse? It is a famous story about the Greek’s war tactic of bringing a huge wooden horse inside the city of Troy. The Greeks hid inside it. They waited for a chance to ambush their enemy. This is like a zero-day attack. But what is a zero-day attack?

You will know what is a zero-day attack is in the next section. You will also know how to find one and prevent it from happening.

What Is A Zero-day Attack?

You might be wondering what is a zero-day attack? A zero-day attack targets a software vulnerability which has no patch yet. That's the traditional zero-day attack definition. But what is a software vulnerability? A software vulnerability is a weakness that an attacker takes advantage of. That is according to Wikipedia.

Here’s a zero-day attack example:

A new messaging application was launch for both Android and iOS devices. Every smartphone user was giving good feedback to the developers. But a cybercriminal discovered a flaw in that messaging app. The cybercriminal can send an international SMS for free. They do this by adding two random numbers at the beginning of the recipient’s contact number.

What is a zero-day attack in the above example? It is the adding of two random numbers at the beginning of the recipient’s contact number. The vulnerability here refers to the sending of an international SMS for free. An attacker continues to exploit this vulnerability while there’s no fix yet.

You might be thinking how are zero-day attacks discovered? You will know more about this in the next section.

What Is A Zero-Day Attack And How To Discover One?

Before antivirus developers rely on known virus signatures to prevent future infection. They are in the dark when it comes to new malware threats. Today this scenario has changed. Preventing an infection relies on advance detection. This principle is also applicable to discovering zero-day attacks. To understand what is a zero-day attack and how to discover it, here’s a sample scenario:

This is like a scout who sees an approaching enemy. The scout doesn’t have any clue about the enemy yet. Using binoculars the scout can see in advance what the enemy looks like. The scout then takes note of the enemy’s appearance and behavior. The scout now knows what the threat is and can prevent an attack from happening.

Advance security measures can prevent zero-day attacks from targeting your system or software. You can discover any threat in advance by following these security tips:

What Is A Zero-day Attack: Security Tip #1 Use A Web Application Firewall

Using a WAF or web application firewall defeats many threats. It’s necessary to install security software with WAF capabilities. A WAF watches over your system for any suspicious activity twenty-four hours a day, seven days a week. Any incoming web traffic is subject to inspection. You will get a report notifying you for any malicious or suspicious activity.

What Is A Zero-day Attack: Security Tip #2 Patch Everything

Most people rely too much on Windows updates. This is not a good security practice. You can go to the developer’s website or contact them yourself about the software patches. A patch contains the software bug fixes and upgrades as well. You need a good patch management software to take care of this. Keeping your system and applications up to date is a good security practice.

What Is A Zero-day Attack: Security Tip #3 Use A Multi-feature Security Application

Using a security application that has many features is advisable. Always ensure that your choice of software has the following features or capabilities:

1. Antimalware protection - a good security application detects and removes the following threats:

  • Viruses
  • Trojans
  • Worms
  • Rootkits
  • Spyware
  • Adware
  • Ransomware

2. Application containerization - use a program that can isolate malware from other apps. It should also isolate unknown apps from other programs. This is possible by containing them inside a container. This way they can’t affect other programs.

3. Vulnerability scanning - a lot of developers observe secure coding practices. This is not enough. They should also think from the perspective of an attacker. Using a vulnerability scanner is a necessary thing to do. This tool will look for vulnerabilities or weaknesses in a system. The devs can now come up with an immediate fix.

What Is A Zero-day Attack: Security Tip #4 Stay Alert

So far our topic “What is a zero-day attack” only talks about the computer side. You haven’t heard anything which targets the human side. There is one and this is what they call a social engineering attack.

The attacker tricks someone to do a certain task by inventing some emotional story. The victim will then click on an email link. Upon clicking this malicious link, the victim’s account gets hacked. Being alert and using our common sense prevents this kind of zero-day attack.


You are now aware of what is a zero-day attack. You now also learned how to discover a zero-day attack. You now understand what is a zero-day attack and how to prevent one. All you need now is an all-in-one security solution. For more information on what is a zero-day attack, please visit this link.

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