Reconnaissance, or recon, is the first step of the kill chain when conducting a penetration test or attack against a data target. This is conducted before the actual test or attack of a target network. The findings will give a direction as to where additional reconnaissance may be required, or the vulnerabilities to attack during the exploitation phase. Reconnaissance activities are segmented on a gradient of interactivity with the target network or device.
Passive reconnaissance does not involve any malicious direct interaction with the target network. The attacker's source IP address and activities are not logged (for example, a Google search for the target's email addresses). It is difficult, if not impossible, for the target to differentiate passive reconnaissance from normal business activities.
Passive reconnaissance is further...