Last Updated on 29 July 2022 by Alastair Digby
Developments in cloud computing and IoT benefitted organizations in many ways over the last decade through digital transformation strategies. The modern organization’s IT infrastructure is now multifaceted and heterogeneous, with a diverse range of devices, servers, computing environments, and networks. Unparalleled flexibility increased productivity, and cost-effectiveness is just some of the benefits organizations see every day from these changes.
However, one downside of all this infrastructural complexity is that it widens the attack surface for threat actors. There are far more Internet-exposed digital assets than ever to exploit, and many ways to exploit them. The adoption of hybrid work models further opens up more entry points to get into your network.
To address the lack of control and visibility that hinders your security and IT teams, there is a growing need for dedicated external attack surface management. But what are the steps involved in the cyber attack process and what exactly does attack surface management entail? This article aims to answer these questions and look in detail at the 5 stages of attack surface management.
Types of Attack Surface
The attack surface for a system, network, or IT environment is the total number of entry points that are exposed to unauthorized users and susceptible to being used as attack vectors. With this definition, it’s important to understand that an attack surface spans physical attack points, Internet-facing digital assets, and people. The following summary of attack surface types should prove useful in grasping why attack surface management is important.
Digital Attack Surface
Internet-facing assets comprise your digital attack surface. These digital assets extend beyond the perimeter of an on-premise network and are accessible to hackers over the Internet. You can further sub-divide the digital attack surface into two types:
- Known assets, such as cloud computing instances, cloud storage, web applications, websites, and VPNs.
- Unknown or shadow IT assets that connect to or persist in your environment without formal approval and could include employee-installed software and cloud services.
The dynamic nature of IT infrastructure sees the digital attack surface expand all the time as new cloud services are provisioned, default configurations are left in place or forgotten about, and employees increasingly work from home. Without visibility over the digital attack surface, serious vulnerabilities easily go unnoticed, including open ports, sensitive data exposure, unpatched software or web applications, and absent access control.
Physical Attack Surface
The physical attack surface includes all the hardware (e.g. laptops, smartphones, USB tokens) that hackers can get physical access to and use that access to infiltrate your network. In the world of shadow IT and hybrid work, the physical attack surface extends to employees accessing corporate applications from unapproved and potentially unsecured smartphones or other devices.
Interestingly, the physical attack surface is not restricted to attackers being in certain physical locations—social engineering techniques, such as USB drop attacks, can provide remote access to physical devices. Physical break-ins or employees allowing entry to your premises are aspects of the physical attack surface.
Human Attack Surface
Human error remains a primary cause of data breaches. The human attack surface includes employees who are susceptible to social engineering attacks, people making misconfigurations, and even malicious insiders.
The larger your attack surface, the more at risk you are from sensitive data breaches and other serious issues. Attack surface reduction is one way to mitigate against potential threats, but actually identifying ways to reduce your attack surface calls for constant vigilance and monitoring as part of a wider attack surface management approach.
Typical Steps in the Cyber Attack Process
You can analyze pretty much any cyber attack and break it down into several distinct steps:
- A reconnaissance phase where threat actors gather intelligence from online digital footprints, Internet-facing vulnerabilities such as open ports or poor website security, and stolen credentials from previous breaches
- Based on information gathered about the attack surface, weaponizing a technique or tool that provides an efficient way to compromise the system or asset and delivering that exploit through the chosen attack vector
- An exploitation and installation phase in which adversaries use techniques to open backdoors into networks, take down security controls, escalate privileges, and maintain access to a compromised system or resource
- Taking actions that achieve the objective of the attack, whether that’s exfiltrating protected health information, installing ransomware, or snooping on intellectual property.
Many sources break down these steps in the cyber attack process more granularly, but this gives you the gist of it.
The 5 Stages of Attack Surface Management
Clearly, managing and monitoring your attack surface is critical if you want to identify changes, test for vulnerabilities, and block potential threats before they turn into full-blown breaches. You need a more complete picture of your attack surface from an attacker’s perspective to better understand the risks associated with all Internet-facing and attacker-exposed assets. That’s where attack surface management comes in.
So, what are the 5 stages of attack surface management? Here is a brief overview of each phase.
Stage 1: Attack Surface Discovery
You can’t protect what you don’t know about, and you can’t reduce an attack surface when you don’t know how wide it is. Attack surface management starts with the discovery of all your Internet-facing digital assets.
Ideally, your solution should automate much of the discovery rather than depending solely on manually inputting the assets that should be monitored. Holistic, complete discovery helps you map out your entire attack surface and get visibility into any shadow IT assets that slipped under the radar. complete
Stage 2: Asset Inventory
An asset inventory takes the information from the discovery phase and organises it in a structured way both for ongoing management and accountability purposes. Later phases of management, including the ability to monitor for or track new changes to your attack surface and potential vulnerabilities, depend on having a well-defined inventory. An inventory adds additional details on who owns the asset and what it’s used for.
Stage 3: Classification
Classification provides a clearer picture of what each asset does, how it intersects with sensitive data, what its compliance requirements are, and how critical it is to your organization. The classification phase makes it easier to pinpoint the security risks across your IT environment and helps you understand which vulnerabilities to prioritize.
Stage 4: Prioritization
When applied to your actual attack surface rather than perceived threats, prioritization provides actionable risk scoring that identifies high risk areas. By getting an objective rating on the likelihood of adversaries targeting particular assets and the risks of them being exploited, you can better focus remediation or mitigation efforts on those real-world high-risk assets. This is similar to and often incorporates vulnerability management approaches that use a common vulnerability scoring system to rank vulnerabilities by severity.
Stage 5: Continuous Monitoring
Monitoring your attack surface on an ongoing basis is an essential function that attack surface management facilitates. The ease at which employees can spin up new cloud instances, install software, or tweak configurations means your attack surface constantly changes. Without comprehensive monitoring, you can’t track these changes and remediate any new vulnerabilities, compliance missteps, or weaknesses emerging within your dynamic environment.
Never underestimate the power of attack surface management. In today’s complex IT landscape, this emerging technology puts visibility and control back in the hands of your organisation and closes security gaps before they’re exploited by attackers. Any attack surface management solution should closely align its features with the five steps of attack surface monitoring outlined above.