Outlook: Filter Messages by Events

🚨 The Signal: Outlook now allows filtering messages by calendar invitations. This feature could be exploited by adversaries to hide malicious calendar invites within legitimate ones, increasing phishing risk.

The Impact

All users are affected by a new filtering option that could be abused for targeted phishing attacks.

• End Users: Increased risk of missing malicious calendar invites due to new filtering options.
• Security Teams: New vector for social engineering attacks requires updated user awareness training.
• Admins: Need to consider how this feature might be leveraged in phishing campaigns.

The Action

1. Review existing phishing simulation campaigns to include calendar invitation-based attacks.
2. Update user awareness training to specifically address malicious calendar invitations and the new filtering feature.
3. Monitor for any reported incidents leveraging calendar invitation filters for social engineering.

Domain: Exchange · Impact: medium · Workload: Exchange Online