9 Steps to Reducing Your Attack Surface

Guest Post

A recent report by Gartner names attack surface expansion as the leading cybersecurity trend to watch for in 2022.

Adoption of technologies such as Internet of Things devices (IoT), cloud applications, complex digital supply chains, open-source code, and more have resulted in the expansion of organization's attack surfaces and exposure to breaches.

Now more than ever, organizations require increased visibility into how their digital environment looks from an external perspective. Viewing your attack surface the same way as a hacker is the best way to spot and remediate attack vectors and security vulnerabilities before they can be exploited.

Generally, the larger the surface, the more entry points there are for hackers to gain unauthorized access to your organization. For that reason, it's critical to institute tools and practices to reduce your exposure as much as possible and ensure proper management and continuous monitoring.

A Large Attack Surface is a Security Risk for Your Business

The attack surface of your business is the collection of all possible entry points that a malicious actor could exploit to gain unauthorized access to your sensitive data or to launch a cyberattack. This includes all of the potential attack vectors and security vulnerabilities that could give an unauthorized person entry to your systems or business.

Common attack surface components include web applications, OS, mobile devices, data centers, physical locks, web servers, Internet of Things devices as well as your employees who can be manipulated into providing sensitive information through a variety of social engineering techniques.

A large attack surface indicates that there are numerous entry points in your systems that hackers can use to gain access to your organization. What's worse is that with so many vulnerable endpoints it can pose a significant challenge for your IT team to manage your environment and remediate vulnerabilities before cybercriminals spot them.

Consequently, the first step to improving your security posture is to reduce your attack surface as early and as much as possible. This begins with an attack surface analysis.

What is Attack Surface Analysis?

Attack surface analysis involves mapping out every area in your organization that could be susceptible to a breach. This analysis is helpful in identifying opportunities for attack surface reduction because it enables your security team to view your attack surface from the perspective of a hacker.

That way you can see which areas in your organization need testing to uncover existing security vulnerabilities and attack vectors. This in turn helps strengthen your security posture by exposing future risks your organization may face.

More Benefits of Attack Surface Analysis

  • IT teams identify security vulnerabilities and attack vectors in your systems and remediate them.

  • Protect your organization from security vulnerabilities that result from third-party risks, employee mistakes, unpatched software, intellectual property infringement among others.

  • Uncover changes in your IT infrastructure that may result in changes in your attack surface and may need to be included in your attack surface management program.

9 Ways to Reduce Your Attack Surface

Once you conduct analysis to map out your attack surface, the next step is to work on reducing it. Here are several ways to achieve that:

1. Close Unused Ports
All communication over the internet is exchanged over ports. As such, they represent a ‘doorway' into your network. A port is considered ‘open' when it is configured to accept incoming packets. The good news is that any ports that are not designed to be used by the public can be closed, shutting the door on any potential attacks.

Tip: Ports under 1024 are called system ports. It is recommended to configure sensitive services such as SSH on user ports instead (1024-49151).

2. Adhere to the principle of least privilege access
Too many admin accounts can pose major security risks to your entire network. Once a single account is compromised, the hacker will have gained full access to all the servers, clients and related network. That's why it's important to separate authorization between certain accounts. Also, ensure your employees have the minimum access privileges needed to do their job and remove redundant roles and duplicate policies.

3. Enable multi-factor authentication and multi-human authentication
Enable MFA authentication for all your critical apps, emails and other cloud services. Whether biometric, one-time based passwords, SMS or email based, MFA is your first line of defense, ensuring stolen passwords alone do not grant malicious actors the keys to your business's critical data. MFA is even more secure if used together with multi-human authentication. MHA requires the person trying to access your systems to first request permission from a trusted third-party before they can login to their accounts.

4. Monitor your active domains
DNS records are often an easy target for hackers because they're often subject to human errors. These errors create vulnerabilities that can be used by hackers. However, this can usually be avoided by employing a robust DNS monitoring strategy to continuously keep track of your DNS performance and notify you of any suspicious activity. A DNS monitoring tool lets you enable domain transfer protection and domain auto-renewal and auto-update to avoid your domain expiring without your knowledge and being flagged as inactive, or being flagged for deletion.

5. Monitor third-party data breaches
Consider investing in a comprehensive third-party monitoring program to help you mitigate the impact of vendor data breaches and supply chain disruptions. Third-party monitoring tools ensure real-time risk analysis and remediation. They also perform continuous monitoring to help with automatic discovery of the most common and potentially dangerous third-party attack vectors and security vulnerabilities such as financial risks, operational risks and compliance risks. This in turn ensures trust and transparency between your organization and your vendors.

6. Reduce your code
Bugs and security vulnerabilities can hide in your code so make sure you're not running code that has unnecessary features or is out-of-date. If possible, simplify your code to reduce the amount that is running on your computer, server, or the cloud. Less code means fewer hiding places for bugs and vulnerabilities which means fewer possible entry points for hackers to exploit.

7. Segment your network
Don't keep all your assets on a single network because if one computer is penetrated, the hacker can gain access to the other devices on the network. Consider using Virtual LANs to separate your large network into smaller segments. Network segmentation can help you increase the security, reliability, and efficiency of your network. VLANs create a difficult defense for a hacker to get through because you can't connect from one VLAN to another. This reduces the risk of infected or untrusted devices infecting your sensitive assets.

8. Invest in cybersecurity awareness training
Can your employees tell if an email is spoofed? Do they know what to do if they get hacked? The most damaging breaches often start with your own employees who can be tricked into downloading malicious files, malware or ransomware through tactics such as phishing, whaling and even tailgating. This is why it's very important to invest in a cybersecurity training program that can educate your employees on cybersecurity best practices.

9. Backup your backups
Always make sure you can recover any information that can be stolen or affected by malware. Make separate backups of servers, clients and network gear. And remember, backup data can be infected too, so use strict protection protocols to keep these backups safe from malicious people.


Once you reduce your attack surface, it should be followed by constant testing, monitoring, testing, and reporting to make sure no new attack vectors or security vulnerabilities are developing. Consider investing in an Attack Surface Management tool (like Quantum Armor) which can help automate your analysis and reduction practices, keeping your organization protected far into the future.

Learn more about how Quantum Armor can help you reduce your attack surface. For a limited time, Quantum Armor licenses are being offered completely free of charge so that you can test-drive our platform 100% risk-free!

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Mary Manzi is a HubSpot certified cybersecurity content marketing manager and social media professional.

About Silent Breach: Silent Breach is an award-winning provider of cyber security services. Our global team provides cutting-edge insights and expertise across the Data Center, Enterprise, SME, Retail, Government, Finance, Education, Automotive, Hospitality, Healthcare and IoT industries.