A successful infiltration of a data source, bypassing network security and other access controls, and the consequent extraction of sensitive data are things that constitute a data breach. The data breach campaign usually begins with research, during which the cybercriminal would probe for holes in the organizations security. The second stage is the attack phase; the hacker would infiltrate an organization’s network exploiting the weakness that has been detected. The third phase, exfiltration, is all about the hacker getting access to the data that the organization has secured and the subsequent successful extraction of the data to some external location.”]
Source: https://hackercombat.com/all-about-data-breaches-how-they-happen-and-their-impact/