The social engineering that occurred on July 15, 2020, targeted a small number of employees through a phone spear phishing attack. Using the credentials of employees with access to these tools, the attackers targeted 130 Twitter accounts, Tweeting from 45, accessing the DM inbox of 36, and downloading the Twitter Data of 7. The attack relied on a significant and concerted attempt to mislead certain employees and exploit human vulnerabilities to gain access to our internal systems. We are working with the appropriate authorities to ensure that the people responsible for this attack are identified.”]
Source: https://blog.twitter.com/en_us/topics/company/2020/an-update-on-our-security-incident