Agentless Security Monitoring
Agentless security monitoring in cybersecurity is an approach that secures and assesses digital assets without requiring the installation of dedicated software or an "agent" on the target systems or endpoints. Instead, it relies on existing infrastructure features and remote communication protocols to gather security and configuration data.
How Agentless Monitoring Works
Agentless solutions perform their functions remotely by leveraging native operating system or cloud functionality to access the target systems. The primary mechanisms used include:
Cloud Provider APIs: In cloud environments (like AWS, Azure, or GCP), agentless tools connect directly to the cloud service provider’s APIs to access metadata, configuration settings, and activity logs. This allows the security solution to assess the security posture of virtual machines, storage buckets, and serverless functions by pulling configuration and policy snapshots.
Standard Network Protocols: For traditional network infrastructure, systems, and IoT devices, the solution communicates over existing protocols like SSH (for Linux/Unix systems), WMI (Windows Management Instrumentation for Windows), and SNMP (Simple Network Management Protocol for network devices). The security tool executes remote commands or requests data directly from the system's native capabilities.
Snapshot Analysis: Some cloud security solutions obtain read-only access to a backup or volume snapshot of a cloud instance's disk, enabling them to perform deep, out-of-band vulnerability or malware scans without affecting the running system.
Advantages in Cybersecurity
Agentless security is particularly favored in modern, dynamic environments like the cloud for several reasons:
Simplified Deployment and Maintenance: Since no software needs to be installed, configured, or updated on each endpoint, deployment is significantly faster and easier, often taking minutes instead of hours or days. This dramatically reduces the operational burden for security teams.
Complete and Automatic Coverage: By connecting centrally via APIs, the solution can immediately cover all workloads across the entire cloud estate, including new ones created through auto-scaling, eliminating blind spots from unmonitored assets.
Zero Performance Impact: Agentless monitoring runs remotely and does not use CPU, memory, or disk resources of the monitored workload, ensuring no negative impact on application performance.
Reduced Attack Surface: Eliminating the need for a third-party agent on the device removes a potential vulnerability that attackers could exploit.
Limitations
While highly efficient for posture management, agentless solutions have certain limitations compared to agent-based security:
Limited Real-Time Visibility: Data collection often relies on periodic API calls or snapshots, resulting in near-real-time rather than truly real-time visibility. This can introduce a delay in detecting threats that happen very quickly.
Reduced Granularity: Since the solution operates outside the host, it may lack the deep, granular insight into the internal workings of a system, such as running processes, specific file activities, or kernel-level events, making it harder to detect complex, subtle threats.
Limited Enforcement: Agentless solutions generally cannot perform immediate, active enforcement actions directly on the host (e.g., killing a process or quarantining a file) because they lack a component running on the device.
Agentless security monitoring, by definition, focuses on securing assets without installing local software, which aligns perfectly with ThreatNG's purely external unauthenticated discovery model. ThreatNG provides a continuous, attacker-centric, agentless view of an organization’s external attack surface, helping to identify and prioritize risks exposed across the internet.
ThreatNG's Agentless Capabilities
External Discovery and Continuous Monitoring
ThreatNG's core is its External Discovery, which is fundamentally an agentless approach. It performs unauthenticated assessments and discovery, mimicking an attacker who has no prior access or software installed on the target systems. This agentless reconnaissance allows ThreatNG to map the organization's entire external digital footprint, including cloud environments, domains, and sensitive code. The benefit of this is Continuous Monitoring, which ensures that any new asset or change that becomes exposed and accessible—such as an unpatched server or a publicly accessible database—is immediately detected, without relying on an internal agent update.
External Assessment and Examples
ThreatNG's agentless external assessments directly reveal security gaps that an attacker could exploit without needing an agent:
Cyber Risk Exposure: This rating identifies exposures like Exposed Ports and Private IPs found on subdomains. This is a classic agentless finding in which ThreatNG externally scans for active services.
Example: ThreatNG identifies that a subdomain, discovered through its agentless discovery, is exposing a MySQL database port (3306) or an SSH port (22) on a public IP. This externally exposed component indicates a high-risk misconfiguration that an attacker could exploit to gain initial access.
Web Application Hijack Susceptibility: This rating is based on the presence or absence of key security headers on subdomains, such as Content-Security-Policy and X-Frame-Options. These headers are checked remotely and agentlessly by analyzing the HTTP response.
Example: ThreatNG checks the external HTTP response of a web application and confirms the lack of automatic HTTPS redirect, revealing a critical security weakness that an attacker could exploit without installing any software.
Mobile App Exposure: ThreatNG evaluates how exposed an organization’s mobile apps are by discovering them in marketplaces and analyzing their contents for hardcoded secrets, including Access Credentials such as APIs and AWS API Keys. This external analysis of the app's components is an agentless technique for finding exploitable secrets.
Investigation Modules and Examples
The investigation modules are built upon agentless data collection:
Subdomain Intelligence: This module is entirely agentless. It includes Ports discovery, identifying publicly accessible services like Databases (MongoDB, SQL Server), Remote Access Services (SSH, RDP), and potentially exposed IoT/OT devices.
Example: Using agentless scanning, ThreatNG discovers an exposed Elasticsearch database port on a subdomain, revealing a source of potential data leakage.
Sensitive Code Exposure: This module identifies public code repositories and the secrets they expose. It relies on agentless scanning of external platforms to uncover digital risks, such as leaked AWS Access Key IDs or Stripe API keys that an attacker could use to pivot into cloud resources.
Technology Stack: This module performs exhaustive, unauthenticated discovery of nearly 4,000 technologies comprising a target’s external attack surface. This is done by analyzing external artifacts such as headers and DNS records, and confirming the presence of components like Cloud Providers or Payment Processing software, all without an agent.
Intelligence Repositories
ThreatNG's Intelligence Repositories (DarCache) provide context to agentless findings:
Vulnerabilities (DarCache Vulnerability): Agentless discovery identifies technologies (e.g., an outdated Apache version). This finding is immediately cross-referenced with NVD, KEV, EPSS, and Verified Proof-of-Concept (PoC) Exploits. This allows the organization to prioritize remediation of a vulnerability that ThreatNG found externally and that an attacker could easily exploit.
Complementary Solutions
ThreatNG's agentless findings offer high-certainty intelligence that can be integrated with other systems:
Vulnerability and Risk Management (VRM) Platforms: ThreatNG identifies a high-risk Known Vulnerability on an exposed subdomain (agentless finding). This finding can be sent to an internal VRM platform. The VRM can then use the Legal-Grade Attribution provided by ThreatNG's Context Engine™ to justify and prioritize the fix over thousands of other lower-certainty issues.
Security Orchestration, Automation, and Response (SOAR) Platforms: When ThreatNG detects a leaked Cloud Credential through Sensitive Code Exposure, the SOAR platform can automatically use this agentless finding to trigger an orchestrated playbook. This playbook could include an immediate rotation of the exposed credential within the cloud provider's IAM system, effectively mitigating the threat before an attacker can exploit it.
Cloud Access Security Broker (CASB) Tools: ThreatNG's Cloud and SaaS Exposure module can flag Unsanctioned Cloud Services. This list of unauthorized external services can be fed into a CASB tool. The CASB can then use this information to create or update internal policies that block network traffic to or from these unsanctioned services, preventing users from accessing them and thereby reducing the attack surface.
