> For the complete documentation index, see [llms.txt](https://shellzerox.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://shellzerox.gitbook.io/docs/monitoring-and-alerts/asset-monitoring.md).

# Asset Monitoring

Understand how asset monitoring helps track changes in a website's external security posture.

***

### Overview

Asset monitoring helps maintain visibility into changes affecting websites and their publicly observable security configurations.

Within SHELLZERO X, Sentinel is the running security agent associated with asset monitoring. Its role is to rescan verified assets and identify changes that may warrant further investigation.

### What Is an Asset?

In the context of external website security, an asset may include a domain, website, hostname, or publicly observable service associated with an organization.

Monitoring these assets can help identify changes in configuration, exposure, or detected technologies.

### Monitoring Scope

| Area                   | What May Require Attention                                                    |
| ---------------------- | ----------------------------------------------------------------------------- |
| Website Availability   | Changes in website reachability or response behavior.                         |
| SSL/TLS                | Certificate changes or encryption configuration issues.                       |
| Security Headers       | Changes to browser security-related response headers.                         |
| Technology Exposure    | Changes in publicly detectable software or version information.               |
| DNS Configuration      | Changes to relevant DNS records.                                              |
| Subdomains             | Newly discovered, changed, or potentially misconfigured subdomains.           |
| Vulnerability Exposure | Newly identified vulnerability matches associated with detected technologies. |

The actual monitoring scope depends on the checks supported by the platform and the information available for each asset.

### How Asset Monitoring Works

The general monitoring process involves:

1. **Identify the asset:** Determine which domain or website requires monitoring.
2. **Verify ownership when required:** Complete any available domain verification process.
3. **Reassess the asset:** Run scans or use supported monitoring functionality to review its external security posture.
4. **Review changes:** Investigate differences that may indicate a configuration issue or new exposure.
5. **Take action:** Verify relevant findings and correct confirmed issues.

Sentinel is associated with rescanning verified assets. The exact scheduling, monitoring intervals, and configuration options should be confirmed through the available platform interface.

### Responding to Changes

Not every change represents a security incident. Websites regularly change their certificates, hosting providers, DNS records, and software configurations.

When a change is identified:

* Confirm that the change was expected.
* Check whether it affects security or availability.
* Verify any associated finding.
* Apply corrective action if a genuine issue exists.
* Reassess the asset after remediation.

### Monitoring Limitations

* Monitoring cannot guarantee detection of every security change.
* Results depend on the checks performed and the information publicly available.
* A detected change does not automatically indicate malicious activity.
* Monitoring frequency and alert delivery should not be assumed unless explicitly provided by the platform.
* Asset monitoring does not replace internal security monitoring or comprehensive vulnerability management.

SHELLZERO X asset monitoring is intended to improve visibility into external security conditions and help users investigate changes that may require attention.