What is Zero-Day Exploit and How to Protect Against it?

Written By Sambita Panigrahy  
Anuraag Singh
Approved By Anuraag Singh 
Published On October 12th, 2023
Reading Time 8 Minutes Reading

Technology is evolving day by day, at the same time, cybercriminals are also becoming sophisticated and coming up with advanced attack techniques. Zero-Day exploit is one of them. This type of cyberattack targets a software vulnerability that is unknown to the software developer or to antivirus providers.

The attacker discovers the software vulnerability, quickly creates an exploit, and then uses it in an attack before anybody else can move to mitigate it. Such attacks are highly likely to succeed because there are no defenses in place. Because of this, zero-day attacks present a significant security risk.

Vulnerability, exploit, and threat are frequently used interchangeably with the phrase “zero-day”. It’s crucial to understand the difference.

  • A threat actor might employ malicious code to take advantage of a Zero-day Vulnerability, which is a recent software flaw or security issue.
  • The method or strategy a hostile actor employs to take advantage of the vulnerability to attack a system is known as a Zero-Day Exploit.
  • When a hacker makes malware available to take advantage of a software vulnerability before the developer of the product has fixed it, this is known as a Zero-Day Attack.

zero day exploit

Who Are the Targets of Zero-Day Exploit?

Usually, cybercriminals target organizations of all sizes. But, here are some of the entities that hackers target the most.

  • Government agencies.
  • Large businesses.
  • Those who have access to important corporate information, such as intellectual property.
  • Numerous home users of a system that is weak, like a browser or operating system Vulnerabilities can be used by hackers to break into systems and create huge botnets.
  • Internet of Things, hardware, and firmware (IoT).
  • Governments have occasionally used zero-day vulnerabilities to attack people, groups, or nations that pose a danger to their national security.

Zero-day vulnerabilities are useful to many parties, hence there is a market where businesses pay researchers who find vulnerabilities. In addition to this “white market,” there are also grey and black markets where zero-day vulnerabilities can be bought and sold for up to hundreds of thousands of dollars without being made public.

Some Known Zero-Day Examples

Below are some high-profile examples that were discovered over the past couple of years.

1. Stuxnet: This malicious computer worm targeted manufacturing units in Iran, India, and Indonesia. In an effort to impede the country’s nuclear program, the major target was Iran’s uranium enrichment facilities. The industrial computers known as programmable logic controllers (PLCs), which run Microsoft Windows, had zero-day vulnerabilities. The worm penetrated the PLCs through bugs in the Siemens Step7 software, causing them to send unexpected commands to assembly-line machinery and ruining the centrifuges needed to separate radioactive material.

2. RSA: In 2011, hackers gained access to the network of security firm RSA using an unpatched flaw in Adobe Flash Player. To select RSA workers, the attackers sent emails with Excel spreadsheet attachments. A Flash file placed in the spreadsheets used a zero-day Flash vulnerability. The attackers installed the Poison Ivy remote administration tool to seize control of the machine when one of the workers opened the spreadsheet. Attackers looked for sensitive information once they had access to the network, copied it, and sent it to other servers under their control. RSA acknowledged that confidential information pertaining to its SecurID two-factor authentication systems, which are used globally for access to sensitive data and devices, was among the material stolen.

3. Zero-day assault on Sony Pictures: A zero-day vulnerability was exploited against the company in late 2014. Sony’s network was seriously disrupted by the hack, and sensitive company information was made public on file-sharing websites. Among the stolen data were details about upcoming movies, marketing plans, and the personal email accounts of senior Sony officials. Sony’s exploited vulnerability’s specifics are still a mystery.

4. Operation Aurora: This zero-day exploit from 2009 targeted the proprietary information of several significant companies, including Google, Adobe Systems, Yahoo, and Dow Chemical. The flaws affected both Internet Explorer and Perforce, which Google used to manage its source code.

5. Kaseya Attack: The infrastructure of Kaseya clients is monitored and managed by the Kaseya VSA software, which has been compromised. In accordance with Kaseya’s public statement, REvil ransomware operators infiltrated 1,500 downstream companies and less than 60 Kaseya clients by utilizing zero-day vulnerabilities to spread a malicious update.

Zero Day Vulnerability Timeline

Basically, the timeline is divided into five phases.

Phase 1: Vulnerability Introduced

Malicious hackers identify unknown security vulnerabilities in software, OS, or hardware components.

Phase 2: Exploit Vulnerability

Then, the attackers choose to exploit those gaps to fulfill their malicious intents.

Phase 3: Vulnerability Disclosure

This is the stage where the vendor acknowledges the presence of vulnerability.

Phase 4: Anti-virus Signs Released

After they identify that a vulnerability has been exploited, anti-virus vendors can quickly recognize its signature and protect against it.

Phase 5: Security Patch Deployment

In this phase, the software vendor will release a security update to address the vulnerabilities.

You see, adversaries exploit a security flaw so quickly that the software vendors don’t stand any chance to create and release an update to fix it.

How to Detect Zero Day Exploit?

Since no patches or antivirus signatures exist that could spot the existence of a zero-day exploit, it is challenging to detect. However, there are certain ways through which you can stay alert for an unknown attack.

Note: All the given techniques can’t detect zero-day exploits directly. However, they can definitely provide you with the context to anticipate potential risks.

1. Vulnerability Scanning

Through comprehensive security solutions, you can continuously scan and monitor networks and systems. In this way, you can keep an eye on and reduce the attack surface by fixing the known issues. 

This approach cannot be used to find all zero-day exploits. Businesses must take action on the scan’s findings, conduct code reviews, and clean their code in order to stop the onslaught. Even for those it does identify, scanning is insufficient. Contrary to popular belief, most companies take time to patch recently reported flaws, however, attackers can act swiftly to exploit a zero-day flaw.

2. Patch Management

When a security flaw is discovered it’s important to patch those gaps as soon as possible. It definitely helps in reducing the probable damage. 

An individual update or collection of updates provided by software developers to remedy technical issues or known security weaknesses is referred to as a “patch.” With patches, new features and capabilities for the application may also be added. It’s important to remember that patches are typically short-term fixes designed to be used until the next significant program release. An effective patch management procedure will take into account the following things:

  • Reviewing releases of security patches
  • According to the seriousness of the vulnerability, prioritizing patching attempts
  • Evaluating patch compatibility and applying several patches to all impacted endpoints

3. Sandboxing

This technique helps isolate and analyze the potentially harmful applications in a controlled environment. Though it doesn’t contribute directly to detecting zero-day exploits, it can certainly help in identifying malicious behavior without risking the production environment.

4. Endpoint Detection and Response (EDR) System

Since EDR provides real-time monitoring of computers, servers, and other devices, it can identify unusual behavior at the host level. 

5. Input Validation and Sanitization

Input validation helps to overcome a lot of issues with the first two approaches. Companies are not exposed while they are working on time-consuming tasks like cleaning code or fixing systems. It is substantially more versatile, has real-time attack response capabilities, and is managed by security experts.

Installing a web application firewall (WAF) on the network edge is one of the most effective ways to thwart zero-day assaults. Thereby, all incoming traffic is inspected by a WAF, which removes malicious inputs that might try to exploit security flaws.

Best Ways to Prevent Zero-Day Attacks

Just like the detection; prevention of zero-day exploits is a complex and ongoing challenge since the target is not yet known. However, you can minimize the risk and impact of this attack if you implement some of the best practices. They are;

1. Keeping Software Up-to-Date

When you regularly update your software, operating system, and plugins, you can significantly reduce the attack perimeter.

2. Application Allowlisting

By implementing application allowlisting, you allow approved and trusted applications to run on your systems.  

3. Using Strong Access Controls

Include Firewalls, network security policies, and different flaw detection tools to strengthen access controls.

4. Security Awareness Training

Sometimes organizations neglect cybersecurity training. These sessions can train employees to not fall into the trap of social engineering attacks and phishing attacks which are mostly used for executing zero-day attacks.

5. Security Information and Event Management (SIEM)

SIEM can centralize the collection, analysis, and reporting of security-related data. That can help you detect and respond to suspicious behavior. 

Final Verdict

A coordinated defense, one that comprises both preventative technology and an extensive reaction strategy in the event of an attack, is required to identify and neutralize zero-day attacks effectively. Therefore, by implementing a comprehensive managed cybersecurity solution, organizations can get ready for these sneaky and destructive incidents.