There are various types of security vulnerabilities for cyber attacks. Businesses are responsible for protecting their organizations from these attacks for legal compliance and for keeping their employees, customers, and data safe. One of the most common of these vulnerabilities is the “zero-day vulnerability.” But let’s see what a zero-day vulnerability is and how hackers exploit it. READ More: 19 Signs of a Hacked Website.
What is the concept of “zero-day,” and what does “zero-day vulnerability” mean?
Software programs are usually vulnerable after release. These vulnerabilities are often unintentional flaws or holes in software programs. For example, a security hole that allows cybercriminals to access organizational data. Software developers are always looking for these vulnerabilities to detect, analyze them, and then provide a patch to eliminate the vulnerability. Patches are released in the next version of the software. However, as you can see, this process is time-consuming. It can sometimes take days, weeks, or even months. Even when a zero-day patch is released, not all users implement it quickly; therefore, hackers around the world can start exploiting it as soon as they discover the vulnerability and before the patch is released. In other words, developers have recently been informed of the vulnerability and have zero days to find a solution to the problem; therefore, such vulnerabilities are called “zero-day vulnerabilities.” In fact, a “zero-day attack” occurs when hackers exploit this flaw before developers have a chance to fix it.
The words vulnerability, exploit, and attack are often used alongside the phrase “zero-day,” and understanding the difference between them is essential.
- A “zero-day vulnerability” is a software vulnerability that is discovered by attackers before the business or software owner becomes aware of it. Therefore, there is no opportunity to release a patch for the discovered vulnerability, and no patches are available for zero-day vulnerabilities; this increases the likelihood of successful attacks.
- A “zero-day exploit” is a method that hackers use to attack systems with a zero-day vulnerability.
- A “zero-day attack” is the use of a zero-day exploit to damage or steal data from a system with a zero-day vulnerability.
What is a zero-day attack, and how does it work?
As mentioned, sometimes hackers or attackers discover program vulnerabilities before software developers do. Therefore, they take advantage of the opportunity and write and implement code to exploit that vulnerability. This code is known as an “exploit code.” For example, an exploit code could victimize software users through identity theft or other forms of cybercrime. Once attackers have identified a zero-day vulnerability, they need a way to access the vulnerable system. They often do this via email. For example, they send an email or any message that appears to be from a known or legitimate source (but is actually from an attacker). This message tries to convince the user to take action, like opening a file or visiting a malicious website. By doing this, malware is downloaded, penetrates the user’s files, and steals confidential data.
Exploits are sold on the dark web for hefty amounts; however, they are valid until developers release patches and all users implement them. Once a vulnerability is discovered and fixed, it is no longer considered a zero-day threat.
In recent years, hackers have acted quickly to exploit vulnerabilities immediately upon discovery. Zero-day attacks are among the most dangerous types of attacks, as usually, the only people who know about them are the attackers themselves. When attackers infiltrate a network, they can immediately attack or sit back and wait for the best time to do so.
Who carries out zero-day attacks?
Attackers who carry out zero-day attacks can fall into various categories depending on the motive of the attack. For example:
Cybercriminals – Hackers whose motivation is often financial exploitation.
Hacktivists – Politically or socially motivated hackers who want their attacks to become media incidents to draw public attention to their cause.
Corporate Espionage – Hackers who spy on companies to gather information about them.
Cyber Warfare – The goal of these attackers is to spy on or attack the cyber infrastructure of another country.
Targets of Zero-Day Attacks
A zero-day attack can exploit vulnerabilities in various systems, including:
- Operating Systems
- Web Browsers
- Office Applications
- Open Source Components
- Internet of Things (IoT)
Therefore, there is a wide range of potential victims, for example:
- Individuals who use a vulnerable system such as a browser or operating system. Hackers can exploit security vulnerabilities to endanger devices and create large botnets.
- Individuals with access to valuable business data.
- Large companies and organizations
- Government organizations
Even when attackers do not specifically target individuals, a large number of people can still be affected by zero-day attacks. The aim of non-targeted attacks is to ensnare as many users as possible.
Examples of the latest zero-day attacks
In 2020, a vulnerability was found in the popular video conferencing platform. In this zero-day attack, hackers could gain remote access to a user’s computer if it was running an older version of Windows. The hacker could fully take over their device and have access to all of their files.
- Apple iOS
Apple’s iOS is often recognized as the most secure smartphone platform. However, in 2020, it fell victim to at least two sets of iOS zero-day vulnerabilities, including a zero-day bug that exposed iPhones to remote attackers.
- Attack on Microsoft Word in 2016/2017
In 2016, Ryan Hanson (a security researcher and consultant from Optiv) identified a zero-day vulnerability in Microsoft Word. This vulnerability, known as “CVE-2017-0199”, allowed an attacker to execute malicious scripts and install malware on a user’s computer after the user downloaded a Word file.
According to Reuters, hackers used CVE-2017-0199 to steal millions of people’s bank accounts before Microsoft developers fixed it in 2017. Interestingly, Hanson was not the only one who discovered CVE-2017-0199; in April 2017, researchers from McAfee and FireEye both reported that they had found this vulnerability.
- Stuxnet Attack in 2010
In 2010, Stuxnet targeted several facilities (including nuclear facilities) in Iran. Stuxnet was a computer worm that infected Windows computers via a USB stick containing malware. The Stuxnet malware then attacked machines with the aim of targeting “programmable logic controllers” (PLCs). PLCs automate machine processes, meaning that Stuxnet could interfere with its target machines.
According to McAfee, Stuxnet destroyed several water treatment plants, power plants, gas lines, and centrifuges at the Natanz uranium enrichment facility and also spawned several offspring, including Duqu (a malware that steals data from targeted computers).
How can we identify zero-day attacks?
Identifying zero-day vulnerabilities can be challenging since they can have various manifestations, such as malicious algorithms, password security issues, and more. Accurate information about zero-day exploits is only available after the exploit is identified. Organizations targeted by a zero-day exploit may observe unexpected traffic or suspicious scanning activity from a client or service. One technique for detecting zero-day attacks involves examining the characteristics of zero-day malware based on how they interact with the target system. Instead of analyzing the code of received files, this technique looks at their interactions with existing software to determine whether they are malicious or not. Additionally, machine learning is used to establish baseline behavior for the system based on past and current interaction data with the program. The more data available, the more reliable the detection becomes.
How does a Zero-Day exploit work?
Zero-day exploits work by taking advantage of a vulnerability in software that is unknown to the developer. This vulnerability is identified and exploited by a malicious actor.
The attack can be successful and result in the theft of information or identity by attackers, or the developer may create a patch to prevent the exploit from spreading. Once a patch is written and deployed, the exploit is no longer referred to as a zero-day exploit.
Security researchers have divided the timeline of a zero-day exploit into seven distinct stages, from the discovery of the vulnerability to the release of a security patch. These stages are as follows:
Stage 1: Vulnerability discovery
A developer creates software that unknowingly contains vulnerable code.
Stage 2: Exploit disclosure
A malicious actor identifies the vulnerability before the developer becomes aware of its existence or has the opportunity to fix or patch it. While the vulnerability is still open, the hacker writes an exploit code and utilizes it.
Stage 3: Vulnerability detection
The development company becomes aware of the vulnerability but does not yet have a patch available.
Stage 4: Vulnerability disclosure
The company and/or security researchers publicly announce the vulnerability, making both users and attackers aware of its existence.
Stage 5: Anti-virus signatures released
If attackers have created zero-day malware specifically targeting the vulnerability, vulnerable companies can quickly identify its signatures and provide protection against it. However, if the vulnerability has been exploited through other means, systems may still remain vulnerable to attacks.
Stage 6: Security patch release
The software development company provides a public fix to address the vulnerability. The duration of this process depends on the complexity and priority of the fix within the product development process.
Stage 7: End of patch utilization
Releasing a security patch does not immediately fix the situation, as it may take users a certain period of time to apply the patch. Therefore, organizations and users need to take action for automatic software updates and pay attention to update notifications.
Systems are vulnerable to attacks throughout the entire process from Stage 1 to Stage 7. However, zero-day attacks can only occur between Stages 2 and 4. Attacks are more likely to happen if protection against the vulnerability is not implemented.
Zero-day attacks are rarely quickly detected, and serious damage can occur as a result. It often takes days, months, or even years for a developer to become aware of a vulnerability in their software, which can lead to attacks and data theft.
How to protect against Zero-Day attacks
Although patching a Zero-Day attack, by definition, is impossible, there are methods that allow organizations to defend against these attacks.
Scanning solutions can simulate attacks on software code, check for errors, and attempt to identify issues that may arise from a software update. However, this approach does not guarantee the detection of all Zero-Day exploits, and scanning alone is not sufficient. Companies must act swiftly based on scan results and review their code to prevent the exploitation of vulnerabilities.
Applying software patches as soon as possible after the discovery of a software vulnerability can help mitigate the risk of an attack. However, if a hacker exploits the vulnerability faster than the patch can be applied, it cannot prevent the attack. The longer the patching process takes, the higher the risk of a Zero-Day attack.
Input validation involves checking any input provided to a program or user to prevent the entry of data with improper formatting into the system. Performing this process, along with vulnerability scanning and patch management, helps protect companies and provides them with the ability to respond to new threats in real-time.
Utilizing a Web Application Firewall (WAF)
One of the best ways to prevent Zero-Day attacks is to use a Web Application Firewall (WAF) at the network edge to inspect incoming traffic and filter out malicious inputs that may target security vulnerabilities.
Zero-Day Initiative (ZDI)
The Zero-Day Initiative is a program that rewards security researchers who disclose vulnerabilities rather than selling them on the black market. The goal of this initiative is to create a community of vulnerability researchers who discover software flaws before hackers do. Additionally, companies offer vulnerability reward programs and provide incentives to individuals who report vulnerabilities to them.
How to protect computers and critical data against Zero-Day attacks?
To protect against Zero-Day attacks and secure your computer and important data, it is essential to follow established cybersecurity practices for individuals and organizations. Several strategies can help you protect your business from Zero-Day attacks:
Keep all software and operating systems up to date
This is necessary because security patches to cover newly identified vulnerabilities are added in newer versions. Therefore, relying solely on software developers to release patches is not enough, and users need to update their programs and apply these patches to ensure their security. You can enable automatic program updates so that your software is updated without manual intervention.
Use only essential programs whenever Possible
The more software you have on your system, the more potential vulnerabilities you will have. Therefore, you can reduce the risk by installing only the programs you need.
Utilize a firewall
A firewall plays a crucial role in protecting your system against Zero-Day threats. You can configure a firewall to allow only essential traffic, ensuring maximum protection.
Educate your organization’s employees
Many Zero-Day attacks capitalize on human errors by users. Training employees and users on good online safety habits helps preserve their online security and protects organizations against Zero-Day exploits and other threats.
Use anti-virus software
Anti-virus software helps keep your devices safe by blocking threats.
How to mitigate Zero-Day vulnerabilities?
To stay vigilant against Zero-Day attacks, organizations should have a proper strategy in place.
Being proactive and informed about the latest risks in the threat landscape is a fundamental step in preventing Zero-Day attacks. This includes using comprehensive security software to block known and unknown threats.
Creating good online safety habits and configuring browser and system security settings are also important in this regard.
FortiGuard Labs at Fortinet is committed to discovering new and emerging threats and providing immediate protection against them in Fortinet products before these threats cause security issues for companies.
Perform System Updates
System updates play a crucial role in protecting companies against the risk of Zero-Day attacks. This includes installing the latest patches, removing expired or obsolete patches, updating drivers, fixing bugs, and patching potential security holes in systems.
Utilize Next-Generation Firewalls
Traditional antivirus software cannot effectively protect companies against Zero-Day threats. Instead of relying solely on such software, companies should seek solutions that prevent unknown Zero-Day malware effectively.
Fortinet Next-Generation Firewalls (NGFWs) combine deeper inspection capabilities and advanced threat detection to not only stop malware but also have enough flexibility to adapt to changes in the threat landscape and protect the company’s network against emerging threats.