IronSights

Penetration testing

Reconnaissance

The first phase of a cyber attack or penetration test, in which the attacker or tester gathers information about the target — including infrastructure, staff, technology stack, and potential vulnerabilities — before attempting exploitation.

Also known asreconinformation gatheringpassive reconnaissanceactive reconnaissance

In plain English

Reconnaissance is the intelligence-gathering phase that happens before an attacker makes their first move. This includes searching public sources (OSINT), scanning internet-facing systems for open ports, and identifying which software versions are running. What attackers find in this phase shapes every subsequent decision about how to attack.

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More terms in the IronSights Glossary.