Trusted workflow abuse is the misuse of normal business channels, such as platform inboxes, contractor portals, or collaboration tools, to deliver malicious content in a way that looks routine. Instead of sending obvious spam from a random address, the attacker uses a path people already trust for work, so the message is less likely to be questioned.
This matters because security controls often focus on email and perimeter filtering, while internal or business-platform messages may be treated as low risk. In practice, trusted workflow abuse is used for phishing, malware delivery, and account takeover attempts. A fake identity may send a document, request a login, or share a link through a legitimate workflow, hoping the victim will open a file, approve a request, or enable active content. Defenses include stronger identity verification, platform monitoring, file and link scanning, conditional access, and user training that treats all business channels as security-sensitive.