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.
UNC6671 Vishing Attacks Target Personal Phones to Steal SaaS Data
Google and Mandiant attribute vishing-based SaaS data extortion attacks to UNC6671, now operating under the Redact, Pink, Helix, and Falcon brands.
Google Threat Intelligence Group and Mandiant track extortion group UNC6671, which uses vishing calls impersonating IT help desks to lure employees to adversary-in-the-middle phishing pages that capture credentials, MFA tokens, and session tokens. The group then registers adversary-controlled MFA devices, pivots through identity providers into Microsoft 365, Okta, and other SaaS applications, and runs automated Python and PowerShell exfiltration scripts. UNC6671 has rotated through extortion brands including BlackFile, Redact, Pink, Helix, and Falcon, and Google tracked over $10.6 million in Bitcoin payments between January 7 and May 12, 2026, with initial demands exceeding $3 million. The actor has hit dozens of organizations in North America, Australia, and the UK, shifting toward high-value financial and legal firms in July 2026.
GhostCode Phishing Kit Bypasses Microsoft 365 MFA to Hijack Accounts in 78 Seconds
eSentire identified GhostCode, a phishing kit abusing Microsoft 365 OAuth device-code sign-in to steal tokens and take over accounts in seconds.
eSentire analysts identified GhostCode in late August, a phishing kit that uses business contact-form messages and an NDA pretext to deliver a password-protected HTML attachment leading victims to a Microsoft device-code sign-in. Victims authenticate on legitimate Microsoft pages, letting the kit obtain a Primary Refresh Token in 32 seconds and register three devices in 78 seconds, with residential proxies matching the victim's location. The kit hides its redirect with encrypted addresses, junk data, and scanner-filtering challenges, and uses GHOSTnet-linked infrastructure during device enrolment. eSentire recommends blocking device-code authentication via Conditional Access, invalidating tokens, and reviewing newly enrolled devices.