Up to 50,000 Office 365 users are being targeted by a phishing campaign that purports to notify them of a missed chat from Microsoft Teams. In reality, the attack aims to steal Office 365 recipients login credentials. The initial phishing email displays the name There s new activity in Teams, making it appear like an automated notification. The phishing landing page also looks convincingly like a Microsoft login page with the start of the URL containing microsftteams .
Source: https://threatpost.com/microsoft-teams-phishing-office-365/160458/