Zero-Day Exploits and How to Defend Against Them

When reading about ransomware attacks or data breaches in the news, you’ll probably run across the term “zero-day exploit.” This type of attack is often at the heart of many widespread attacks because it’s one of the most difficult for traditional cybersecurity methods to detect.

A recent example was the breach of the Microsoft Exchange Server that was discovered earlier this year. Hackers took advantage of four zero-day exploits that allowed them to take control of company mail servers. It’s estimated that 30,000 businesses in the U.S. were impacted, many of them small and medium businesses.

What makes zero-day exploits more difficult to defend against than your run-of-the-mill virus or malware?

It’s because they represent a new vulnerability that hasn’t yet been addressed with a security patch. It’s also a vulnerability that is not in any threat database that legacy antivirus software uses to identify threats.

Why Zero-Day Exploits are So Dangerous

A zero-day exploit is an attack code that is written to take advantage of a zero-day vulnerability. There are many types of vulnerabilities in software, operating system, and firmware code that appear all the time. These vulnerabilities leave a door open in the system for hackers to exploit a loophole in the code and use it to gain some type of device access.

Vulnerabilities can do things like:

  • Allow a hacker to gain system permissions as a user
  • Make it possible to elevate a newly added user to an administrator
  • Provide access to execute code on the device (taking it over)
  • Allow a hacker to plant ransomware or other malware
  • Provide access to all data on the device’s hard drive

Newly found vulnerabilities are why you often see security patches being issued in OS and software updates. Developers find vulnerabilities and then they fix their code so those weaknesses can’t be exploited, and then issue that code update to users.

What’s different about a zero-day vulnerability is that it hasn’t been detected yet by the OS or software developer. Thus, no patch has been developed or issued for it.

The term “zero-day” refers to the number of days a software vendor has been aware of the vulnerability. “Zero” meaning they aren’t aware of it.

Exploits are code written by attackers to take advantage of vulnerabilities in software and OS code. So, zero-day exploits are those exploits that take advantage of zero-day vulnerabilities.

In other words, the hackers find out about a vulnerability before the software developer does and begin attacking any computers, servers, or other devices that have that vulnerability.

It’s only after attacks have begun to be noticed that the software developer is made aware of the vulnerability and begins working on a patch to stop the zero-day exploit.

Unknown & Undetectable by Traditional Antivirus

What makes zero-day exploits so dangerous is that they take advantage of an unknown issue and one that hasn’t yet had a patch or update issued. So, the user isn’t able to fix that vulnerability until the developer catches up with the hacker and issues an update.

Traditional antivirus/anti-malware that is signature-based, isn’t built to detect zero-day exploits. It detects malware by matching suspicious code to a database of known threats looking for a threat signature. Zero-day exploits aren’t yet in threat databases, so they slip by these older legacy tools.

How Do You Defend Against Zero-Day Exploits?

One of the best ways to defend against zero-day exploits is to use a managed Endpoint Detection and Response (EDR) system. EDR uses artificial intelligence and machine learning to detect threats rather than relying on a database of known code exploits.

Here are some of the ways that EDR helps companies defend against zero-day threats.

Looks for Behaviors

EDR looks for the strange behaviors that indicate the presence of malicious code. This could be a program performing a function that it usually doesn’t perform, or permission being changed through a suspicious method.

By looking for the footprints of an attack, EDR can detect even zero-day threats that haven’t yet been cataloged anywhere.

Uses Zero-Trust Tactics

Endpoint detection and response systems help companies deploy zero-trust security tactics. These are tactics designed to combat any type of network threat, even those that are zero-day and unknown.

Some typical zero-trust tactics include:

  • Application safe listing (only allowing certain applications to run commands)
  • Application ring-fencing (restricting the commands one program can give another)
  • Adding multi-step user authentication (including geo-based challenges)

Proactively Hunts for Threats

EDR is designed to proactively scan and monitor your network and endpoints for any threats rather than just sitting back and waiting for something to be detected. This helps you catch any potential threat before it can be unleashed throughout all your devices and cause major problems.

Learn More About Managed EDR to Prevent Zero-Day Attacks

Twin State Technical Services can help your Quad Cities area business with a strong defense strategy against zero-day attacks.

Contact us today for a consultation. Call 563-441-1504 or contact us online.

 

References linked to:

https://www.tsts.com/infrastructure-network-solutions/cyber-security/

https://en.wikipedia.org/wiki/2021_Microsoft_Exchange_Server_data_breach

https://www.tsts.com/blog/managed-endpoint-detection-and-response/

https://www.tsts.com/contact/

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