Phishers targeting admins are becoming more popular due to the greater range of attacks than can be conducted through an admin account. With admin credentials, attackers can potentially create new accounts under an organizations domain, send mail as other users, and read others user’s email. For this reason, it is important to be aware of phishing scams that are not targeting an organization’s users, but rather their administrators. To gain access to an administrator’s account, phishers have started creating campaigns that are disguised as Office 365 admin alerts.
Source: https://www.bleepingcomputer.com/news/security/phishers-target-office-365-admins-with-fake-admin-alerts/