Hackers Use Passkey-Themed Phishing to Hijack Microsoft 365 Accounts and Steal Cloud Data
Microsoft reports passkey-themed phishing campaigns hijacking Microsoft 365 accounts via AiTM and device-code flows, then exfiltrating cloud data.
Microsoft researchers identified passkey-themed phishing across cloud intrusions observed since May 2026, where callers posing as IT support direct victims to lookalike sign-in pages. The flows include adversary-in-the-middle phishing and device-code authentication, letting attackers capture usable sessions even when MFA succeeds, followed by rogue MFA registration for persistence. Attackers enumerate tenants via Microsoft Graph and collect SharePoint, OneDrive, and Exchange data at rates below 1,000 items per hour; lure domains include passkeyhelpdesk.com and setupmypasskey.com.
Passkey-themed social engineering leads to identity and cloud compromise
Microsoft tracks ongoing cloud intrusions where passkey-themed helpdesk lures enable AiTM credential theft, MFA persistence, and SharePoint data theft.
Microsoft Security Research is tracking active cloud-based intrusions, observed since May 2026, that begin with helpdesk impersonation calls and SMS lures urging urgent passkey, MFA, or SSO updates. The lures lead to adversary-in-the-middle phishing or device-code authentication flows that capture credentials and session tokens or grant actor access, after which the actors add authentication methods, conduct Microsoft Graph reconnaissance, and download SharePoint and OneDrive content via REST APIs. Phishing domains embed victim organization names as subdomains (e.g., contoso.add-passkey[.]com), are often registered with Nicenic, and go operational within hours. Microsoft advises revoking sessions and removing unauthorized authentication methods for confirmed compromises.
New N0va Phishkit Targets North America and EU: A Growing Identity Risk for SOCs
ANY.RUN researchers uncovered the N0va phishkit targeting government, technology, consulting, and healthcare organizations across North America and the EU via device code phishing.
The N0va phishkit uses lures imitating Microsoft Teams, SharePoint, OneDrive, DocuSign, Google Drive, Dropbox, Zoom, and Adobe Sign to draw victims into a device code authentication flow. After the user completes legitimate authentication, N0va captures access and refresh tokens and abuses token-exchange and device-registration mechanisms to establish persistent SSO access to corporate resources. Because the flow relies on real Microsoft authentication, it can evade MFA-focused detections, and token access can outlive takedown of the phishing page. ANY.RUN says it observed the campaign in sandbox sessions, with targeting spanning government, technology, consulting, and healthcare sectors.
NovaCookies Campaigns Abuse Genuine Docusign Notifications to Steal Microsoft 365 Sessions
NovaCookies AitM phishing kit, a Sneaky 2FA variant, uses genuine Docusign lures to steal Microsoft 365 sessions at hundreds of organizations.
Island disclosed NovaCookies, a $320/month adversary-in-the-middle phishing-as-a-service platform that relays Microsoft 365 sign-ins through attacker infrastructure to capture credentials, MFA codes, and authenticated sessions. Campaigns abuse genuine Docusign envelopes and Microsoft/Google redirect hops so each step looks legitimate, with lure domains on .vu and alternating-case labels such as PwPt-sHaRe. Proofpoint assesses NovaCookies as a Sneaky 2FA variant with added flows for Okta and Entra domains federated to GoDaddy, and a fully managed PhaaS model. It has targeted hundreds of organizations in the U.S., U.K., Canada, Germany, Israel, and the U.A.E., and is advertised via Telegram with anti-analysis checks like a Cloudflare gate.
ZDI-26-629: Microsoft Azure Entra ID OAuth Device Code Grant Information Disclosure Vulnerability
Zero Day Initiative disclosed an unauthenticated information disclosure vulnerability (CVSS 5.8) in Microsoft Azure Entra ID's OAuth device code grant flow.
ZDI published advisory ZDI-26-629 describing an information disclosure vulnerability in Microsoft Azure Entra ID related to the OAuth device code grant. Remote attackers can disclose sensitive information without authentication. ZDI assigned a CVSS 3.1 score of 5.8; no CVE identifier is listed in the advisory text.
Attackers use passkey-themed scams to hijack Microsoft 365 accounts
Microsoft tracks ongoing M365 cloud intrusions since May using passkey-themed helpdesk vishing, AiTM phishing, and device-code abuse.
Microsoft Security Research has tracked active cloud intrusions since May in which attackers posing as IT helpdesk staff lured employees with fake passkey/MFA enrollment requests. Attacks used adversary-in-the-middle phishing pages, device-code authentication flows, and Teams messages from compromised accounts. Attackers registered their own MFA methods, enumerated tenants via Microsoft Graph, and accessed SharePoint, OneDrive, and Exchange Online data, throttling activity below 1000 files/emails per hour.
Passkey-themed phishing attacks lead to Microsoft 365 data theft
Microsoft links ShinyHunters- and Helix-affiliated actors to passkey-themed vishing and device-code phishing that compromises Microsoft 365 accounts and steals cloud data.
Microsoft attributes passkey- and SSO-themed social engineering activity, observed since May 2026, to Storm-3121 (linked to ShinyHunters and Falcon) and Storm-3032 (tied to BlackFile members now operating as Helix). Attackers impersonate corporate IT help desks by phone or SMS, urging fake passkey, MFA, or SSO updates and directing victims to adversary-in-the-middle phishing pages or device-code authentication flows that yield credentials, session tokens, and OAuth tokens. Post-compromise behavior includes Microsoft Graph enumeration of users, SharePoint, and OAuth grants, plus persistence via attacker-controlled MFA methods. Google Threat Intelligence tracks related activity as UNC6671, linked to the BlackFile, Helix, Falcon, Pink, and Redact extortion gangs.
Hackers Pose as IT Support to Hijack Microsoft 365 Accounts With Fake Passkey Alerts
Microsoft warns of vishing campaigns by Storm-3121 and Storm-3032 hijacking Microsoft 365 accounts via fake passkey alerts, adding attacker-controlled MFA and exfiltrating cloud data.
Microsoft Security Research has tracked the campaign since May 2026: callers posing as IT helpdesk staff tell employees to urgently update passkeys, MFA, or SSO settings via domains such as add-passkey[.]com and contoso[.]add-passkey[.]com. The lures lead to adversary-in-the-middle phishing or device-code authentication flows that yield credentials, session tokens, or OAuth tokens, after which attackers enroll their own MFA methods for persistence and run Microsoft Graph reconnaissance. They then collect SharePoint, OneDrive, and sometimes Exchange Online data at deliberately low rates (often under 1,000 files or messages per hour), with python-httpx seen in high-volume file access. Microsoft attributes initial access tradecraft to Storm-3121 and Storm-3032, linked respectively to ShinyHunters/Falcon and BlackFile/Helix extortion operations.