GhostCode Abuses Microsoft Entra Device Enrollment to Maintain Access After Token Revocation
eSentire exposes GhostCode, a device-code phishing kit that abuses Microsoft Entra device enrollment to persist even after stolen tokens are revoked.
eSentire's Threat Response Unit observed GhostCode campaigns in late August 2026, using BEC-style social engineering that impersonated procurement staff, including BJ's Wholesale Club, via Salesforce contact forms. Victims received password-protected HTML lures disguised as a FlipBook document portal, with junk-data padding, HTML comment injection, and AES-256-GCM encrypted redirects gated by anti-bot checks. The kit exploits the OAuth 2.0 device authorization grant, prompting victims to approve real Microsoft device-code sign-ins with MFA. Within 78 seconds of approval, attackers registered three Entra devices and obtained a Primary Refresh Token, so rogue device registrations persist even after session token revocation.
BigBear Microsoft 365 phishing service bypassed MFA at 258 organizations
CloudSEK found the BigBear 2.0 phishing-as-a-service platform bypassed MFA at 258 organizations and captured over 5,000 Microsoft 365 credentials.
CloudSEK researchers gained administrator access to the BigBear 2.0 phishing-as-a-service control panel and found it had exfiltrated 5,137 credential records, including 474 completed MFA-bypassed authentications, 1,032 plaintext passwords, and 4,148 session cookies across 3,331 victim IPs in 40+ countries. The Evilginx2-based AitM proxy intercepts credentials and authenticated session cookies, and custom JavaScript interferes with FIDO2/WebAuthn to force weaker authentication. The panel is leased to at least five affiliate operators via Telegram exfiltration bots, and geo-matched residential proxies cover 69 countries to evade detection.