Agentless Attack Surface
The Agentless Attack Surface refers to the comprehensive collection of an organization’s digital assets, cloud infrastructure, and external exposures that cannot be monitored or secured using traditional software agents. In modern cybersecurity, this surface encompasses components where installing a host-based sensor is either technically impossible, operationally impractical, or contractually restricted.
As organizations migrate to cloud-native environments and rely heavily on third-party services, the portion of the network that supports "agents" (like servers and laptops) is shrinking relative to the vast ecosystem of managed services, APIs, and ephemeral resources. Securing this surface requires technologies that use cloud APIs, disk snapshots, and external scanning rather than installed software.
Core Components of the Agentless Attack Surface
The agentless attack surface is distinct because it relies on the provider's infrastructure rather than the user's operating system. It primarily consists of the following elements:
Cloud-Managed Services: Infrastructure-as-a-Service (IaaS) components where the user does not have access to the underlying operating system. Examples include cloud storage buckets (Amazon S3, Azure Blob), managed databases (AWS RDS, Google Cloud SQL), and load balancers.
Serverless Functions: Code execution environments (like AWS Lambda or Azure Functions) that run for milliseconds and dissolve. These ephemeral assets do not persist long enough for an agent to install, register, and report telemetry.
SaaS Applications: Third-party software platforms (such as Salesforce, Slack, or Microsoft 365) where the organization owns the data and configuration but has zero control over the hosting servers.
Containers and Kubernetes: While agents can run as sidecars, many containerized environments are designed to be immutable and lightweight, making the overhead of security agents undesirable.
External Digital Footprint: The public-facing assets visible from the internet, including registered domains, subdomains, DNS records, and SSL certificates. These are by definition "agentless" because they are viewed from the outside in.
Shadow IT: Unsanctioned devices, software, and cloud instances spun up by employees without IT approval. Since IT is unaware of them, no agents are ever installed, leaving them exclusively within the agentless attack surface.
Why the Agentless Attack Surface is Critical
Understanding this specific attack surface is vital for a holistic security strategy because it represents the "blind spots" of traditional security tools.
Zero Impact on Performance Agent-based security often degrades performance by consuming CPU and memory. The agentless attack surface is secured via "side-scanning" or API queries, meaning security checks occur out of band without slowing production workloads.
Complete Visibility Agents only work where they are installed. If a developer creates a new virtual machine and forgets to install the security agent, that machine is invisible to an agent-based tool. An agentless approach scans the cloud provider's API to discover all assets, ensuring 100% inventory coverage.
Resistance to Tampering Attackers often try to disable security agents upon gaining access to a server. In an agentless model, security monitoring occurs at the cloud or virtualization layer, which is inaccessible to attackers within the workload.
Securing the Agentless Attack Surface
Defending this surface requires a different set of methodologies compared to traditional endpoint protection.
Cloud Security Posture Management (CSPM): These tools use read-only API access to scan cloud configurations for security risks, such as open ports or missing encryption, without touching workloads.
External Attack Surface Management (EASM): This involves scanning the public internet to identify exposed assets and vulnerabilities that an attacker could see, providing an "outside-in" view.
Snapshot Scanning: Security tools take a momentary snapshot of a cloud disk, analyze it for malware and vulnerabilities in a separate environment, and then discard the snapshot. This allows for deep inspection without an agent.
Frequently Asked Questions
What is the difference between agent-based and agentless security? Agent-based security requires installing a small software program (sensor) on every server or device to monitor activity in real-time. Agentless security uses cloud APIs and external scanning to assess risk without modifying the target system.
Can agentless security stop attacks in real-time? Generally, agentless security is better for discovering vulnerabilities, misconfigurations, and dormant malware (posture management). Real-time blocking of active processes typically requires an agent, though some agentless cloud firewalls can block network traffic.
Does an agentless attack surface include employee laptops? Typically, no. Employee laptops are endpoints that usually support and require agents (EDR). The agentless attack surface focuses on cloud assets, managed services, and external exposures where agents cannot be deployed.
Why is "Shadow IT" considered part of the agentless attack surface? Because Shadow IT comprises assets the security team is unaware of, it inherently lacks installed security agents. Therefore, they can only be discovered and secured using agentless methods such as external scanning or network traffic analysis.
ThreatNG and the Agentless Attack Surface
ThreatNG is designed to secure the Agentless Attack Surface because its architecture operates without installed software, agents, or authenticated connectors. By utilizing purely external, unauthenticated discovery, ThreatNG provides visibility into the cloud assets, SaaS platforms, and digital supply chain components that traditional agent-based tools cannot reach.
External Discovery of Agentless Assets
The core challenge of the agentless attack surface is visibility. ThreatNG solves this by mapping the organization’s digital footprint from the "outside-in," capturing assets that exist beyond the reach of internal IT management tools.
Cloud and Infrastructure Identification: ThreatNG proactively discovers the cloud services hosting an organization's data without requiring API keys or side-scanning permissions. It identifies specific Cloud & Infrastructure providers, distinguishing between Storage & CDN (e.g., AWS/S3, Microsoft Azure, Google Cloud Storage) and PaaS & Serverless platforms (e.g., Elastic Beanstalk, Heroku, Vercel). This ensures that ephemeral serverless functions and storage buckets are cataloged even if no agent is installed on them.
SaaS Platform Enumeration: Since agents cannot be installed on third-party SaaS applications, ThreatNG uses SaaS Identification to detect their usage. It catalogs specific services found in the external footprint, such as Salesforce, Slack, and Zendesk, effectively mapping the "Shadow IT" portion of the agentless surface.
DevOps and Repository Discovery: ThreatNG identifies tools used in the software supply chain, including GitHub, GitLab, and Bitbucket. This is critical for agentless security, as these platforms host the code and configurations that define the infrastructure, yet they exist outside the corporate firewall.
External Assessment of Cloud and Supply Chain Risks
Once agentless assets are discovered, ThreatNG assesses their configuration and security posture using external validation techniques.
Cloud Exposure Assessment: ThreatNG evaluates Cloud Exposure by checking for publicly accessible storage buckets and misconfigured cloud services. For example, it can verify whether an AWS S3 bucket or Azure Blob identified during discovery is publicly accessible, a common "agentless" vulnerability that can lead to massive data leaks.
Subdomain Takeover Susceptibility: This assessment specifically targets the "dangling" agentless resources. ThreatNG performs DNS Enumeration to find CNAME records pointing to third-party services (like Fastly, Shopify, or Unbounce) that have been deprovisioned. It cross-references these records with its Vendor List to identify subdomains vulnerable to takeover, a risk that internal agent-based scanners miss because the target "host" no longer exists.
Supply Chain & Third-Party Exposure: ThreatNG calculates a security rating for third-party vendors that comprise the agentless attack surface. By analyzing the Technology Stack, it provides a risk score for the external partners (e.g., a payment processor like WorldPay or a chat widget like Intercom) that the organization relies on, ensuring that risks in the extended ecosystem are visible.
Investigation Modules for Non-Invasive Forensics
ThreatNG’s investigation modules allow security teams to drill down into specific threats without needing access to the underlying operating system.
Sensitive Code Discovery: This module secures the "Code as Infrastructure" layer. It scans public repositories for Sensitive Code Exposure, identifying hardcoded secrets, API Keys, and Cloud Credentials. This is vital for agentless security because a leaked AWS key grants an attacker control over the cloud environment without requiring them to exploit a server or bypass an endpoint agent.
Domain and Subdomain Intelligence: ThreatNG analyzes metadata from external assets. It analyzes HTTP Headers and DNS configurations to determine if a web asset is susceptible to Web Application Hijack. For example, it checks if a serverless app hosted on a subdomain is missing Content-Security-Policy (CSP) headers, identifying a risk that exists purely at the application delivery layer.
Intelligence Repositories for External Threat Context
ThreatNG enriches the agentless attack-surface view with threat intelligence that correlates external assets with active risks.
Vulnerability Correlation (DarCache Vulnerability): ThreatNG matches the identified technologies (e.g., a specific version of Nginx or Apache visible on a public server) with Known Exploited Vulnerabilities (KEV). This allows organizations to identify vulnerable agentless appliances (like VPN gateways or load balancers) that cannot support an EDR agent but are critical entry points for attackers.
Compromised Credentials (DarCache Rupture): ThreatNG tracks Compromised Emails and passwords associated with the organization. This is the primary defense for SaaS applications where "Identity is the Perimeter." If the credentials for a Salesforce admin are leaked, ThreatNG alerts the team, treating the identity compromise as a breach of the agentless attack surface.
Continuous Monitoring and Reporting
The agentless attack surface is highly dynamic, often changing with every code commit or cloud deployment.
Continuous Footprint Monitoring: ThreatNG continuously scans for new subdomains, buckets, and services. If a developer spins up a new Google Cloud instance or registers a new domain, ThreatNG detects it immediately, keeping the inventory up to date without waiting for a scheduled agent deployment.
Risk-Based Reporting: Reports prioritize findings based on external exploitability. A report might highlight "High Risk: Exposed S3 Bucket" or "Critical: Leaked API Key," focusing the team's attention on the specific agentless exposures that require immediate configuration changes rather than patching.
Complementary Solutions
ThreatNG provides the "Outside-In" view that validates and enhances the "Inside-Out" view provided by internal security platforms.
Cloud Security Posture Management (CSPM) ThreatNG validates CSPM findings externally.
Cooperation: CSPM tools use API access to read internal cloud configurations (e.g., "Bucket policy allows public access"). ThreatNG confirms the risk by attempting to discover and access the bucket from the public internet. If ThreatNG detects the bucket, the risk is deemed exploitable.
Cloud Access Security Broker (CASB) ThreatNG identifies Shadow IT that CASBs miss.
Cooperation: CASB tools monitor traffic from managed devices to known cloud apps. ThreatNG discovers unknown cloud apps and unmanaged instances (Shadow IT) that employees use on unmanaged devices. This provides a comprehensive view of SaaS usage, enabling the CASB team to update their blocking policies.
Third-Party Risk Management (TPRM) ThreatNG provides technical validation for vendor assessments.
Cooperation: TPRM teams rely on vendors to self-report their security posture. ThreatNG provides independent, technical verification. If a vendor claims to be secure, ThreatNG’s Supply Chain Exposure rating validates this by checking their actual external footprint for vulnerabilities, ensuring that the "agentless" reliance on that vendor is backed by data.
Frequently Asked Questions
How does ThreatNG secure assets where we can't install agents? ThreatNG secures these assets by scanning them from the internet, just like an attacker would. It checks for exposed ports, misconfigurations, and software vulnerabilities in HTTP headers and banners, providing a security assessment without requiring OS access.
Can ThreatNG find "Shadow" cloud accounts? Yes. Through Subdomain Discovery and DNS Enumeration, ThreatNG can identify resources hosted on cloud providers (like dev-app.s3.amazonaws.com) that are linked to your organization's domain but managed outside of the central IT cloud account.
Does ThreatNG replace CSPM? No. CSPM provides deep internal configuration auditing (e.g., checking IAM roles). ThreatNG complements CSPM by providing an external attack-surface view, identifying which misconfigurations are exposed to the public internet.
