Cybersecurity NewsExplainedGuides

Step By Step Introductive Insight Into Zero-Day Attacks, Guide.


Zero-day attacks are one of the things that send shivers down the spine of software manufacturers.  Software vendors are always looking for weaknesses in their products. When they find a problem, they issue a code fix, also known as a “patch”. However, sometimes attackers find a weakness before the vendor does. This is called a “zero-day vulnerability”.

In this article, we will explain how zero-day attacks work, discuss some of the most common zero-day vulnerability trends, and provide examples of zero-day attacks.

What are Zero-Day Attacks?

Security vulnerabilities in computing systems are common and attackers exploit them to gain unauthorized access, cause damage, or compromise a system. Observers document these defects in public repositories such as the National Vulnerability Database (NVD).

Due to the severity of these defects, both software vendors and independent security researchers are always searching for new vulnerabilities in software products. When they find them, the vendors issue a patch that addresses the security issue, and users can then install the patch to protect themselves.

A zero-day attack occurs when attackers exploit a software loophole before the vendor has become aware of it. Since there is no patch available, attackers can easily exploit them. This makes the threat vulnerabilities a severe security threat.

Attackers need a delivery mechanism to exploit a zero-day vulnerability. In many cases, the delivery mechanism is through phishing. The exploiters disguised a legitimate correspondent or actors to gain the trust of the victims. The message tries to convince a user to perform an action such as opening a file or visiting a malicious website, unwittingly activating the exploit.

Adding to the severity of this defect is the fact that the most likely malicious entities to use them are advanced cyber threat actor groups.

However, they tend to use this exploit only for high-value targets such as government organizations, and medical or financial institutions. This reduces the vulnerability’s visibility, increasing the lifespan before vendors issue a patch.

It’s important to note that after they develop a patch, users must still update their systems. Failure to do so will leave a system vulnerable to a zero-day exploit.

The Types of Zero-day Attacks

There are two types of zero-day exploits. They are;

Targeted zero-day attacks are usually executed against high profile targets, such as government or public institutions, large organizations, and senior employees who have privileged access to corporate systems, access to sensitive data, intellectual property or financial assets.

Non-targeted zero-day attacks are typically targeted at a large number of home or business users who use a vulnerable system, such as an operating system or browser. Often, the attacker’s goal will be to compromise these systems and use them to build massive botnets.

A recent example was the WannaCry attack, which used the EternalBlue exploit in the Windows SMB file protocol to compromise over 200,000 machines in one day. Non-targeted attacks can also target hardware, firmware and Internet of Things (IoT).

Examples of Hackers Exploiting This Vulnerability

Below are three substantial examples of high-profile zero-day attacks, illustrating the severe risk zero-day attacks pose for organizations. It labels the attack distribution and data exploited through the vulnerability.


In 2006, Stuxnet was arguably highlighted as the world’s first cyber weapon. A cyber digital malware used to break into Iran’s uranium enrichment centrifuges.

According to different sources, many professionals believe that the National Security Agency (NSA) created the zero-day exploit named Stuxnet.

Stuxnet effectively infected a specific industrial control system and sped up or slowed down the centrifuges to the point where they destroyed themselves.

Moreover, during this internal spread through Iranian monitoring systems the zero-day attack made it appear that systems were operating normally.


In 2011, threat actors used an unpatched vulnerability in Adobe Flash Player to gain entry into the network of security vendor RSA.

Consequently, the threat actors distributed emails via Excel spreadsheet attachments to RSA employees; the attachments triggered a Flash file, which essentially exploited the zero-day Flash vulnerability. The data stolen included key information used by RSA customers in Secure ID security tokens.


In 2014, a zero-day attack infiltrated Sony Pictures through its vulnerability. While the details of the vulnerability exploited in the attack remain unknown, the attack however brought down Sony’s network, and threat actors leaked sensitive data on file sharing sites of the corporation.

Furthermore, these include personal data about Sony employees and their families, internal correspondence, data on executive salaries, and copies of unreleased Sony films.

The infiltrators used a variant of the Shamoon wiper malware to clean off multiple systems on Sony’s corporate network.

How Can You Protect Yourself and Systems?

With 108 zero-day vulnerabilities discovered in 1,825 days, that works out at an average of a new exploit every 17 days.

However, these statistics can be misleading due to inconsistent changes. Nonetheless, the reality is that researchers discover such defects almost every day. This means you can’t afford to ignore it as you may be the next victim. 

Based on professional directives, start by ensuring a comprehensive approach to network security. Active defensive strategy should involve consistent system scans to discover blindspots and vulnerabilities.

Additionally, provide all endpoint protection to make sure admins have the ability to see into all network traffic, including encrypted traffic, and connected devices or tools, including Linux-powered IoT machines.

Search for an endpoint security tool that actively monitors for and systematically responds to chains of anomalous code execution, and which can provide contextualized alerts for an entire attack chain.

Solutions like Sentinel One allow your employees to use the tools they need to get their work done while at the same time systematically taking action against malicious code execution directly from source.


If there’s one thing we can learn from the last 5 years of zero-day exploits, it is that zero-days are a constant threat that organizations and individuals need to have a coordinated strategy to deal with.

When the next news headline has everyone buzzing, be sure you have the ability to check, patch and defend against any attacker trying to leverage it against your network.