What is an External Security Sensor (ESS)?
An ESS is an external monitoring sensor that continuously observes an organization's digital assets from the outside — the way an attacker sees a target.
TL;DR
- An External Security Sensor (ESS) is a CyberRank monitoring component that continuously observes a company's attack surface from an external perspective.
- It detects configuration changes, new assets, and new risk signals on a regular cadence.
- ESS data feeds security ratings and the rating dashboard — nothing to install.
Short definition
An External Security Sensor (ESS) is a CyberRank monitoring component that continuously observes a company's attack surface from an external perspective — detecting configuration changes, new assets, and new risk signals on a regular cadence.
How does an External Security Sensor work?
Instead of assessing security once a year, an ESS keeps an always-current view of what is exposed to the internet. Changes like a new subdomain, an expiring certificate, or a suddenly open port are detected in the next monitoring cycle.
ESS data underpins CyberRank's security rating calculations and early warnings in the webapp, so security teams can act on findings before attackers exploit them.
What are some practical examples?
- ESS detects a new subdomain created by the marketing team without a security review.
- An expiring TLS certificate is flagged before it causes a service outage.
- Suspicious DNS record changes trigger an alert for review.
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