Gather Victim Identity Information

Adversaries may gather information about the victim’s identity that can be used during targeting. Information about identities may include a variety of details, including personal data (ex: employee names, email addresses, etc.) as well as sensitive details such as credentials.

Adversaries may gather this information in various ways, such as direct elicitation via Phishing for Information. Information about users could also be enumerated via other active means (i.e. Active Scanning) such as probing and analyzing responses from authentication services that may reveal valid usernames in a system. Information about victims may also be exposed to adversaries via online or other accessible data sets (ex: Social Media or Search Victim-Owned Websites).

Gathering this information may reveal opportunities for other forms of reconnaissance (ex: Search Open Websites/Domains or Phishing for Information), establishing operational resources (ex: Compromise Accounts), and/or initial access (ex: Phishing or Valid Accounts).

Source:
https://attack.mitre.org/techniques/T1589