Zero Day Attack: How It Works & Prevention Guide

The Zero Day Attack is among the most dangerous attacks because it exploits a vulnerability that is completely unknown to the software vendor or the public. When you are hit by a zero day attack, the company that makes the software has had "zero days" to fix the problem.

Why does this matter to you? A successful zero day exploit in cyber security can mean hackers steal your data, take over your computer systems, or simply shut down your operations. It can lead to massive financial losses and a complete loss of trust. 

In this section, we will explore this significant security threat and the essential steps you can take for zero day attack prevention.

What is a Zero Day Attack?

A zero day attack can be understood as an assault that leverages a previously unknown vulnerability in a computer system or application. This is a flaw that the software developer has not yet patched or even identified.

In other words, a zero day exploit in cyber security is a piece of code written to take advantage of this secret flaw. Once an attacker finds this vulnerability, they develop an exploit and use it to launch an attack before any security patch exists.

The name, Zero Day Attack, refers to the fact that the vendor has zero days to prepare a fix when the exploit is first used. It is to be noted that this vulnerability exists in software that you likely use every day, such as your operating system, web browser, or common office applications.

Secure Against Zero Day

Anatomy of a Zero Day Attack

To understand this better, let us now discuss the systematic process behind a typical zero day attack. The entire process usually comprises four main steps.

1. Finding the Zero Day Vulnerability

The process begins when an attacker, or a group of attackers, finds a zero day vulnerability. This vulnerability is nothing but an error in the programming code of a software application.

This error allows the attacker to perform an action that the software developer never intended. For example, the vulnerability might allow a hacker to write data to a protected memory space.

2. Developing the Zero Day Exploit

Once an attacker identifies the flaw, they develop a specific tool called a zero day exploit. This exploit is a carefully crafted code sequence.

The purpose of this code is to interact with the vulnerable software in a way that triggers the flaw and gives the attacker control. This exploit code acts as the key that unlocks the system's defenses.

3. Launching the Zero Day Attack

The attacker uses the zero day exploit to launch the actual attack. This often involves delivering the exploit code to the target system.

This action takes place through various means, such as a malicious email attachment, a compromised website, or a network intrusion. The attack aims at installing malicious software, i.e., malware, onto the target system without the user's knowledge.

4. Creating the Patch

The final stage is the vendor's response. This happens after the attack is discovered, which is often only after real-world attacks have already taken place.

The software vendor then rushes to write a fix, which is called a patch. This new patch is nothing but a security update that eliminates the specific vulnerability. Once the patch is available, the vulnerability is no longer a "zero day" but a "known" vulnerability.

Also Read: What Is a Whaling Attack? How It Works & Prevention

Why Zero Day Attack? 

Now, the question arises, why zero day attack? What motivates sophisticated attackers to spend vast time and resources finding these rare vulnerabilities? The primary motivations are highly diverse and depend on the target.

• Financial Gain: Many attacks aim at stealing sensitive financial information, such as credit card numbers or banking credentials. This is the most common motivation for criminal organizations.
• Espionage: Nation-states and government-sponsored groups often use a zero day exploit in cyber security to spy on foreign governments, steal intellectual property, or gather sensitive political data.
• Sabotage: In some cases, the goal is simply to disrupt or destroy the target's infrastructure. This includes taking down critical utilities or manufacturing systems.
• Fame and Recognition: Some independent hackers aim to gain notoriety within the hacking community by discovering and using a highly valuable zero day.

The high value of a zero day vulnerability means that these exploits are often sold on underground markets for millions of dollars. The one who sells this exploit gets paid for their findings.

Effective Zero Day Attack Prevention Strategies

Traditional security defenses, e.g., signature-based antivirus software, cannot stop a zero day attack because the attack signature is entirely new. Therefore, successful zero day attack prevention requires moving beyond these older security models.

1. Implementing Zero Day Attack Detection with Behavior Analysis

Effective zero day attack detection relies on observing the behavior of the programs rather than looking for a known malware signature. This means that instead of asking "Is this program known bad?", the system asks: "Is this program doing something unusual or suspicious?"

• Network Traffic Analysis: This method involves continuously monitoring all network communications. The system identifies unusual patterns, such as a program suddenly sending a massive amount of data to an external server or attempting to bypass security protocols.
• Endpoint Detection and Response (EDR): EDR tools focus on monitoring activity on individual devices, i.e., endpoints. They look for actions like unexpected memory access, unauthorized file changes, or strange system calls. This helps in catching the zero day exploit before it can fully execute its payload.
• Sandbox Environments: This strategy allows the system to open a suspicious file or run a questionable code in an isolated environment, i.e., a sandbox. This environment prevents any potential malware from actually reaching and harming your live operating system.

2. Adopting Proactive Defense Measures

Beyond real-time detection, several proactive steps can significantly reduce your system's exposure to a zero day attack.

• Principle of Least Privilege: This requires that every user, program, and process should have only the minimum permissions necessary to perform its specific task. If a zero day exploit compromises a low-privilege application, it cannot easily move to control the entire system.
• Application Whitelisting: This strategy ensures that your system only allows specific, approved applications to run. Therefore, any unknown or malicious software, including a zero day exploit payload, cannot execute.
• Network Segmentation: This involves dividing a large network into smaller, isolated sub-networks. If an attacker successfully compromises one segment, they cannot immediately jump to the other critical areas of the network, i.e., the attack remains contained.
• Regular and Prompt Patching: While a patch for a true zero day does not exist, maintaining your systems with the latest security updates for known vulnerabilities is still a vital step. Many attacks use exploits for vulnerabilities that are a few days or weeks old, not true zero days.

3. Using Advanced Hardware-Level Security

Modern security also extends into the hardware itself. The chips and processors in your devices now play a vital role in security.

• Trusted Platform Module (TPM): A TPM is a secure cryptographic processor chip that is designed to carry out hardware-based security functions. It helps ensure that your system boots up securely and that its integrity is not compromised by a zero day exploit.
• Memory Protection: Modern operating systems and CPUs use specific technologies to prevent an exploit from executing code in memory locations intended only for data. This technique significantly makes it harder for a zero day exploit to work.

Also Read: Dictionary Attack in Cybersecurity - How it Works and How to Stop?

Zero Day Attack vs. N-Day Attack: Key Differences

It is important to understand the specific differences between a zero day attack and an N-day attack, as this clarifies the true nature of the threat. While both involve exploiting a vulnerability, the key difference lies in the time the vulnerability has been known and patch availability.

Let us now understand the key distinctions between these two types of attacks.

Zero Day Exploit in Cyber Security: Case Studies

Let us now discuss a few notable examples of a zero day exploit in cyber security to show the real-world impact of these threats.

• Stuxnet (2010): This highly sophisticated cyber weapon used four separate zero-day vulnerabilities to attack the programmable logic controllers (PLCs) of industrial machinery. It aimed at physically damaging Iran's nuclear program. Stuxnet demonstrated the immense destructive potential of multiple chained zero-day exploits.
• WannaCry Ransomware (2017): This global ransomware attack exploited a vulnerability in the Microsoft Windows operating system that the US National Security Agency (NSA) had reportedly kept secret. Although a patch for this specific flaw was later released, many systems had not yet applied it, leading to widespread infection.

Also Read: Spear Phishing: Learn About #1 CEO fraud

Conclusion

Understanding the zero day attack is only the first step. True security comes from acting on this knowledge. Our commitment is to provide you with a comprehensive cyber defense strategy that includes advanced behavior-based zero day attack detection and proactive security architecture.

We focus on securing your business against the threats of tomorrow, ensuring your systems are not just patched but truly resilient. 

Contact us today to learn how our solutions can integrate the latest behavioral analysis techniques to protect your critical assets from the most sophisticated threats.

Key Takeaways

So, with the above discussion, we can say that the zero day attack represents a serious challenge to modern cyber security. Keeping this in mind, here are the essential points you should remember about this threat:

• Definition: A zero day attack targets a software vulnerability that is completely unknown to the vendor and the public, meaning zero days have been available to create a defensive patch.
• The Exploit: A zero day exploit in cyber security is a specific piece of code crafted to take advantage of this secret flaw to compromise a system.
• Detection Challenge: Traditional, signature-based security tools cannot detect these attacks because they lack a known signature to match.
• Advanced Detection: Effective zero day attack detection relies on monitoring the behavior of programs and network traffic for anomalies or suspicious activities, rather than known malware patterns.
• Proactive Prevention: Zero day attack prevention requires security architecture measures, such as implementing the Principle of Least Privilege and Network Segmentation, to limit the attacker's ability to move within the network even if the initial exploit succeeds.
• High Value: These vulnerabilities are highly prized by sophisticated attackers, nation-states, and criminal groups for espionage, financial gain, or sabotage.

Frequently Asked Questions (FAQs) on Zero Day Attack

What is the difference between a zero day and a 'known' vulnerability?

A zero day vulnerability is a flaw that the vendor does not know about, i.e., a patch does not exist. A 'known' vulnerability is one that has been publicly reported, and the vendor has typically released a patch for it. Attackers often target systems that have failed to apply the patch for a known vulnerability.

How long does a vulnerability remain a zero day?

A vulnerability remains a zero day only until the vendor releases a software patch that fixes it. Once the patch is available, it is no longer a zero day, even if many users have not yet applied the fix.

Can antivirus software stop a zero day attack?

Traditional, signature-based antivirus software often cannot stop a zero day attack because the attack code is entirely new and does not match any known signature in the antivirus database. You require advanced solutions, e.g., Endpoint Detection and Response (EDR), that use behavioral analysis for effective zero day attack detection.

What should I do immediately if I suspect a zero day exploit in cyber security has affected my system?

If you suspect an attack, you should immediately isolate the affected system from the network. This action aims at preventing the exploit from spreading further. Thereafter, you should initiate a full forensic analysis to understand the scope of the breach and identify the specific vulnerability that was targeted.