Riding the Rails: Arctic Wolf Tracking Threat Actors Abusing Railway PaaS for Microsoft 365 Token Compromise
Arctic Wolf has recently observed a phishing campaign targeting Microsoft 365 that abuses the OAuth device code flow to trick victims into providing authentication codes. Threat actors use Railway’s Platform-as-a-Service (PaaS) infrastructure (a trusted cloud platform with valid IP addresses) to host attack components, allowing the activity to blend in with normal traffic. This enables threat actors to steal valid access and refresh tokens and bypass multi‑factor authentication protections.