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In Security Last updated: September 15, 2023
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As cyber security measures continue to improve, however on the other end, cyber crimes are also becoming more sophisticated. Nowadays, cyber hackers are smartly stealing data without users’ knowledge. One such attack is the Zero-Day attack.

This article will dive into Zero-day vulnerabilities and exploits, how they work, and how to detect and prevent such attacks.

What is Zero-Day Vulnerability, Exploit & Attack?

Zero-day Vulnerability: A security defect in computer software or a system found by a cyber attacker but unknown to the developer and software vendor is a zero-day vulnerability.
It is impossible to mitigate this hidden security flaw, as nobody knows about it, even after its launch. It takes months or a year to understand and fix the vulnerability.

The term ‘Zero-Day’ is given to this attack because there were zero days for the software developer to fix this security flaw.

Zero-day Exploit: On the other hand, a zero-day exploit is a piece of code that may install malware or spear phishing to gain unauthorized access to a system.

Zero-day Attack: Cyber attackers release a known exploit on a developer’s computer, network, or software system in a zero-day attack. This attack could be very harmful since there were no known defenses to protect it during launch.

But what are the dangers of zero-day attacks and the motives? Read on to find out!

Why are Zero-Day Attacks Dangerous?

Zero-day attacks are creeping into the cybersecurity landscape. The biggest challenge of this attack is the mystery of the Zero-day exploit or the security vulnerability unknown to the developers.

Sometimes, this security flaw remains unknown for months. The software professional can’t fix the vulnerability until he discovers the attack. Zero-day attacks are so deadly that anti-virus software can’t detect them through a signature-based scan.

The user or organization suffers a heavy loss with this attack. Many cyber criminals use Zero-day exploits to make money with the help of ransomware.

According to the checkpoint website, the attackers made 830,000 attempts within 72 hours when they found the Log4j vulnerability.


Motives of Zero-Day Attackers

  • Data Stealers: The main goal of the cyberattacker is to seek financial gains. They steal financial details and sensitive data like bank statements, UPI codes, etc.
  • Hackavist: Some attackers target government facilities for political or social reasons. They may leak sensitive data or deface websites.
  • State-sponsored Attackers: Nowadays, government and nation-state agencies use zero-day exploits. They usually attack espionage, cyber warfare, or intelligence gathering.
  • White-Hat Hackers: White-hat hackers don’t have malicious intentions. They use zero-day vulnerabilities to check and ask the software developers to fix them.
  • Vandalish Attackers: Some attackers exploit vulnerabilities to create chaos, damage systems, or disrupt services for revenge or thrills.
  • Black Marketers: Cyber attackers may sell zero-day vulnerabilities and exploits to the highest bidder, including nation-states, criminals, and corporations.
  • Criminal Networks: Few criminal organizations use zero-day attacks such as drug trafficking, human smuggling, and other crimes.

While these are just a few types of hackers, it is important to be aware of cyber threats so that steps can be taken for their prevention and to maintain better cyber security.


How Does a Zero-Day Attack Happen?

The attackers target government departments, hardware, software, IOT, large businesses and organizations, vulnerable systems, and other critical infrastructures.

Let us understand how zero-day attacks work.

Step I

Cyber attackers try to find security vulnerabilities in some well-known applications, platforms, or websites. This vulnerability can be any flaw in the software, like code with bugs, missing encryption, or an unprotected part of the code to get unauthorized access.

Step II

The attacker spots the vulnerability in the software before the developer and the software vendor. He understands the vulnerability and creates a zero-day exploit. The attacker uses this code to conduct attacks.

The zero-day exploit can be a code with malware that may further distribute more malware after installation. These codes are so dangerous that they may spread throughout the system and may damage them.

The exploit code can also act as an admin or perform malicious activities. At this time, the developer is unaware of the vulnerability. The attacker may also sell this vulnerability or zero-day exploit into the black market at a higher price.

Step III

The attacker plans a targeted or mass attack and distributes the Zero-Day exploit according to his intentions. The attacker can distribute the exploits to a targeted person or a large group through mass phishing emails or spear phishing.

Step IV

The victim downloads or installs the malware via phishing emails or clicking on malicious websites. This malware affects the browser, operating system, or applications and hardware.

Step V

The software vendor discovers the security flaw either by testing or by the third-party customers. He informs the software developer team about the defect.
The software professionals resolve the vulnerability and release a patch. Anyone who updates the software in their system is no longer susceptible to the security flaw.


Types of System Vulnerabilities in a Zero-Day Attack 

Here are some of the vulnerabilities that zero-day attackers target:

  • Operating system flaws: The attackers can gain deep access to a system by exploiting vulnerabilities in operating systems, applications, or servers.
  • Web Browsers and Plugins: Exploiting web browsers is a common tactic attackers use to gain complete access to a system and project. The attackers also target web plugins, browser extensions, and browser plugins like Java and Adobe Flash.
  • Hardware vulnerabilities: Some zero-day attackers target hardware vulnerabilities like a mobile or computer system’s firmware and chipset. These flaws can be complicated to patch, as they require hardware updates.
  • Network Protocols: The attackers exploit security vulnerabilities in network protocols or network devices such as routers and switches. This vulnerability may disrupt the system’s network connection and allow unauthorized access.
  • Computer Worms: The hackers can intercept computer worms as they infect the host. This surprise zero-day attack of worms can be difficult to detect as they spread throughout the internet, creating havoc.
  • Zero-Day Malware: This malware is unknown and has no specific anti-virus software available for it. The attacker can distribute this malware through malicious websites, emails, and other vulnerable websites and applications.
  • Other Vulnerabilities: These vulnerabilities can be broken algorithms, missing data encryption, security issues with passwords, missing authorization, etc.

How to Identify Zero-Day Attacks

Usually, zero-day attacks are difficult to detect by software professionals and vendors. Once they identify the exploit, they find detailed information about the zero-day exploit.

Here are a few ways to identify zero-day attacks.

  • Code analysis: Code analysis checks the file’s machine code to detect suspicious activity. This method has some limitations. Detecting the malware or flaw is still difficult if the code is complex.
  • Behavior Analysis: The unexplained rise in traffic, unusual file access, and unusual system processes can detect zero-day attacks.
  • Intrusion detection systems (IDSs): IDSs can detect malicious activity. They also identify vulnerabilities and known exploits.
  • Sandboxing Technique: The Sandboxing technique isolates the app from the rest of the system. It can help prevent zero-day attacks from spreading to other system parts.
  • Vulnerability Scanning: Vulnerability scanning also plays a vital role in detecting zero-day attacks. It identifies, scans, prioritizes, remediates, and mitigates the vulnerabilities.
  • Patch Management: Patch Management is applying patches to vulnerable systems. Patch management is usually dependent on vulnerability management scanning.

How to Prevent Zero-Day Attacks

Zero-day attack prevention is one of the most challenging parts, as the vulnerabilities are unknown to the software developers. Here are some best practices to prevent zero-day attacks for businesses and organizations.

  • Security Program: Building a well-versed security program, considering the type of business and its risks, and creating a solid team.
  • Managed Security Service Provider: Finding an appropriate security service provider can monitor businesses 24/7. They stay vigilant to potential threats like phishing and protect organizations from cyber crimes.
  • Install a Robust Web App Firewall: A robust firewall scans the incoming traffic, checks for threats, and blocks all malicious sites.
  • Improve Patch Management: Improved patch management capabilities avoid zero-day attacks. It effortlessly mitigates all the software vulnerabilities.
  • Vulnerability Management: Prioritize the vulnerability management program as it remediates and mitigates all the vulnerabilities and reduces the overall risks of the software project.
  • Update Software Consistently: Regularly updating the software reduces the probability of zero-day attacks. Cybercriminals have vast knowledge about an organization’s security software. Hence, it’s mandatory to update such software regularly.
  • Frequent Testing: When the software developers do frequent simulations and testing, it will help them clarify where the zero-day vulnerability can occur.
  • Educate and Provide Tools to Employees: Educate your employees about cyber attacks and social engineering. Provide them tools to report and detect phishing, spear phishing campaigns, and monitor malicious attempts or threats.
  • Backup Plan: Always keep a recovery backup plan so the organization doesn’t lose sensitive data.

Examples of Zero-Day Attacks

Let’s see some real examples of zero-day attacks.

#1. Stuxnet

The NSA and CIA’s security team discovered this zero-day attack in 2010. It is a malicious computer worm. Stuxnet targets supervisory control and data acquisition (SCADA) systems. These systems damaged Iran’s nuclear program. This attack exploited multiple zero-day vulnerabilities in Windows to dominate industrial systems and their operations.

#2. Heartbleed

Heartbleed is a zZero-day vulnerability that affects an encryption library called OpenSSL. In 2014, this flaw allowed attackers to steal sensitive data from websites and services that used the affected version of OpenSSL. This zero-day attack highlighted the importance of promptly addressing security vulnerabilities and protecting data from attacks.

#3. Shellshock

Shellshock is a zero-day vulnerability discovered in the Bash (Bourne-Again Shell) command line interpreter in September 2014. This zero-day attack allowed the cyber attackers to gain unauthorized access and execute arbitrary commands.

#4. Adobe Flash Player

The hackers discovered multiple zero-day vulnerabilities with Adobe Flash Player. In this zero-day attack, the cyber actors used malicious flash files in email attachments or websites to gain complete control over the systems.

#5. Zoom

The attackers found a zero-day vulnerability in the Zoom video conferencing platform in 2020. In this zero-day attack, the attacker could access the user’s system remotely if the user used the older Windows version. The hacker could control the user’s system and access all the data if he targeted a particular user.

#6. Apple IOS

Apple’s iOS became the victim of a zero-day vulnerability, letting attackers remotely compromise iPhones in 2020 and September 2023. Pegasus spyware exploited vulnerabilities and targeted IOS devices, as many professionals, journalists, and government employees use them.

#7. Operation Aurora

Operation Aurora aimed to attack organizations that included Google, Adobe Systems, Akamai Technologies, Rackspace, Juniper Network, Yahoo, Symantec, and Morgan Stanley. 

Google discovered this attack in 2010, while the cyber attack began in mid-2009 and continued until the end of the year. The cyber actor exploited the zero-day vulnerability in Internet Explorer to access Google and other companies.

#8. Twitter

In 2022, Twitter experienced a data breach due to a zero-day attack. The attackers found a 5.4 million list of accounts using a zero-day vulnerability on this social media platform.

What to do if you Become a Victim of a Zero-Day Attack?

  • Isolate the affected systems when the attack is confirmed.
  • Keep digital evidence like screenshots, reports, or other information to investigate.
  • Engage with your security team, which specializes in handling such attacks, to take the necessary precautions.
  • Mitigate the vulnerability ASAP with the software and security teams. Also, recover the affected systems and devices.
  • Analyze how the zero-day attack occurred and plan a security management program for it.
  • Notify stakeholders, legal teams, and higher authorities about the attack.

Remember, it is important to consider taking legal action if the organization suffers a significant data breach.


Zero-day attacks are a big concern for the cyber security landscape. Hence, it’s challenging to detect and mitigate them. Following the best practices to avoid these dangerous cyber security attacks is required.

Moreover, building a solid software security team with security researchers and developers can patch zero-day vulnerabilities.

Next up, the best cybersecurity compliance software to stay secure.

  • Anuja Shende
    Anuja has been in SEO field for the past 5.5 years and writes SEO-friendly content. She has completed her degree in computer engineering. She loves to sing, play guitar and ukulele, and read spiritual and non-fictional books.
  • Joy R Bhamre

    Joy R Bhamre is a Google certified Digital Marketing Specialist, Content Writer & Editor as well as a Cambridge-certified English Language Trainer with over 14 years of corporate experience.

    She is an English Literature… read more

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