Understanding Calendar Invite Phishing: How Attackers Abuse .ICS Files and How to Defend Against IT
Barracuda Networks, Thursday, August 6th, 2026
Barracuda explains how attackers weaponize calendar invites and .ics files to bypass email security.
Barracuda details a phishing technique that abuses calendar invitations and .ics attachment files. Because calendar invites are handled differently from ordinary messages, they can slip past email security controls that would flag equivalent content in a standard email.
Attackers use the invites to deliver credential-harvesting links that appear in a trusted calendar context.
The article outlines defenses, including tightening how invites from external senders are processed.