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.
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.
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.
Crypto customers targeted by scammers after email marketing provider breach
Attackers exploited a Brevo SAML SSO flaw to access 138 accounts and phish crypto customers of Trezor, CoinTracking, and BitBox.
An attacker exploited a flaw in Brevo's SAML SSO handling to access 138 customer accounts on September 10; six accounts were used to send phishing emails and contacts were exported from 43 accounts. Crypto firms Trezor, CoinTracking, and BitBox confirmed customers received phishing emails, with Trezor warning roughly 347,000 newsletter subscribers. The Trezor-themed email cited a fabricated STM32 microcontroller entropy bug and urged recipients to enter wallet backups through a malicious link. Exported contact lists could fuel future targeted phishing attacks.
Mirage2FA Surge Hits 4,500 US and EU Companies, Abusing Microsoft 365 Login Flows
Mirage2FA phishing-as-a-service campaign hit ~4,500 organizations, mostly US, stealing Microsoft 365 passwords and session cookies to bypass 2FA.
ANY.RUN research links the Mirage2FA phishing-as-a-service toolkit to 4,532 unique organization email domains between 2024 and 2026, with the US accounting for 63.7% of victims. The kit uses adversary-in-the-middle login flows to harvest credentials and session cookies, bypassing MFA on Microsoft 365 accounts. Researchers recorded more than 9,000 potential compromise events and estimated 48% of targeted email addresses were potentially compromised. Hijacked sessions extend to SSO-connected services, enabling impersonation, fraud and further compromise.