Search Open Websites/Domains

Adversaries may search freely available websites and/or domains for information about victims that can be used during targeting. Information about victims may be available in various online sites, such as social media, new sites, or those hosting information about business operations such as hiring or requested/rewarded contracts.[1][2][3]

Adversaries may search in different online sites depending on what information they seek to gather. Information from these sources may reveal opportunities for other forms of reconnaissance (ex: Phishing for Information or Search Open Technical Databases), establishing operational resources (ex: Establish Accounts or Compromise Accounts), and/or initial access (ex: External Remote Services or Phishing).

ID: T1593
Sub-techniques:  T1593.001, T1593.002
Tactic: Reconnaissance
Platforms: PRE
Version: 1.0
Created: 02 October 2020
Last Modified: 15 April 2021

Procedure Examples

ID Name Description
G0034 Sandworm Team

Sandworm Team researched Ukraine's unique legal entity identifier (called an "EDRPOU" number), including running queries on the EDRPOU website, in preparation for the NotPetya attack. Sandworm Team has also researched third-party websites to help it craft credible spearphishing emails.[4]


ID Mitigation Description
M1056 Pre-compromise

This technique cannot be easily mitigated with preventive controls since it is based on behaviors performed outside of the scope of enterprise defenses and controls. Efforts should focus on minimizing the amount and sensitivity of data available to external parties.


Much of this activity may have a very high occurrence and associated false positive rate, as well as potentially taking place outside the visibility of the target organization, making detection difficult for defenders.

Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.