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.
Attackers Use Passkey Phishing to Hijack Microsoft Cloud Accounts and Exfiltrate Data
Microsoft details two campaigns: million-email CEO impersonation ACH fraud and passkey-themed vishing that hijacks Microsoft cloud accounts for data theft and extortion.
Microsoft disclosed a campaign that sent over one million CEO-impersonation scam emails between August 3-5, 2026, targeting U.S. accounts payable departments with fake ServiceNow subscription invoices to induce ACH transfers, using generative AI to tailor templates. A second campaign detected since May 2026 uses passkey/MFA-themed voice phishing posing as the IT help desk, redirecting victims via SMS to counterfeit Microsoft sign-in pages and adversary-in-the-middle or device-code flows to hijack accounts. Post-compromise activity includes adding attacker-controlled authentication methods, high-volume Microsoft Graph activity, SharePoint and OneDrive downloads, and mailbox collection via REST APIs. Microsoft attributes initial access to Storm-3121 (linked to ShinyHunters and Falcon extortion) and Storm-3032 (UNC6671, a BlackFile splinter operating the Helix extortion brand).
Operation RapidRust: APT36 Deploys RUSTYSHADE, RUSTYMOVE, PSNATCH, and BASHNATCHnew
Zscaler details Operation RapidRust: APT36 deploys four new tools including RUSTYSHADE, a Rust backdoor using private GitHub repos for encrypted C2.
Zscaler ThreatLabz documents Operation RapidRust, a campaign by Pakistan-aligned APT36 deploying four new tools: RUSTYSHADE, a 64-bit Rust Windows backdoor that uses attacker-controlled private GitHub repositories with a hardcoded PAT and AES-256-GCM-encrypted messages for C2; RUSTYMOVE; PSNATCH, a PowerShell file stealer that scans Office documents, archives, media, and databases modified in the last 120 days and exfiltrates up to 5 GB per run to per-machine GitHub repositories; and BASHNATCH. The backdoor was dropped via PowerShell from attacker-controlled Backblaze B2 storage and supports screenshots, webcam capture, file listing, downloads, and shell command execution.
IT help-desk vishing tricks executives into handing over Microsoft 365 access
Arctic Wolf tracks PREY-0058 (linked to UNC6671), a vishing campaign stealing Microsoft 365 session tokens via AiTM panels for SaaS data theft and extortion.
Arctic Wolf is tracking a campaign, PREY-0058, sharing tradecraft with Google Threat Intelligence Group's UNC6671, in which callers posing as internal IT talk employees through fake passkey/MFA setups. Operator-controlled adversary-in-the-middle pages harvest passwords and MFA approvals to seize session tokens, then actors enumerate and bulk-exfiltrate data from SharePoint, OneDrive, Exchange, and Box. Extortion brands include BlackFile, Pink, Helix, Cinder, and Redact; targets are mostly US-based executives in construction, healthcare, real estate, finance, and professional services, with exfiltration shifting to residential proxies like NodeMaven.
IT Help Desk Impersonation Lets Hackers Bypass MFA
Arctic Wolf tracks PREY-0058 posing as IT help desk to steal Microsoft 365 sessions via AiTM panels, then extorting executives after SaaS data theft.
Arctic Wolf documented a threat cluster tracked as PREY-0058 that impersonates internal IT help desk staff by phone, luring Directors, VPs, and executives to authentication-themed URLs formatted as victim-organization lure domains. Adversary-in-the-middle panels intercept credentials and MFA approvals, and stolen sessions are replayed through residential proxies such as NodeMaven from IPs matching the victim's geo-location and ASN, defeating impossible-travel alerts. Attackers perform discovery against SharePoint and Entra ID, then harvest data from OneDrive, Exchange, and Box before issuing extortion demands. Defenders are advised to require managed devices, use phishing-resistant MFA like FIDO2, enable Continuous Access Evaluation, and monitor sign-ins, SharePoint SearchQueryPerformed, and MailItemsAccessed events.
14th September – Threat Intelligence Report
Check Point weekly digest: Microsoft's record 974-vuln Patch Tuesday ships two actively exploited Windows zero-days; IDScan.net, Mathspace, Revolut suffer breaches.
Microsoft's September 2026 Patch Tuesday addressed a record 974 vulnerabilities, including two actively exploited privilege-escalation zero-days, CVE-2026-85880 and CVE-2026-81963, plus 20 flaws allowing unauthenticated remote code execution. Disclosed breaches include IDScan.net (identity documents), Mathspace (over 1 million people via Metabase CVE-2026-72898), Revolut, and Florida DMV (ShinyHunters). GitLab fixed critical CVSS 10.0 path traversal CVE-2026-85706, and MikroTik fixed chainable RouterOS flaws CVE-2026-67276 and CVE-2026-86060. The report also covers the PuzzleMask LLM jailbreak technique, GoldFactory's Gigabud Android fraud, and the BlueMoon Chromium exploit chain (CVE-2026-85046).
Week in review: Linux rootkit deployed on F5 BIG-IP APM devices, Cisco FMC bugs exploited
Weekly roundup: Cisco FMC and N-able N-central zero-days exploited in the wild, MikroTik RouterOS hijacks, Microsoft Patch Tuesday ships two exploited zero-days.
State-sponsored and financially-motivated attackers are actively exploiting CVE-2026-20079, a critical authentication bypass in Cisco Secure Firewall Management Center (FMC), alongside CVE-2026-20316. N-able issued an emergency hotfix for CVE-2026-86218, a critical pre-auth RCE in the N-central RMM platform exploited in the wild. CERT Polska disclosed six RouterOS vulnerabilities being chained to hijack internet-exposed MikroTik devices. Microsoft's September 2026 Patch Tuesday shipped a record patch count including two zero-days, while roughly 67,000 Trezor customers faced phishing after a shipping-partner breach and researchers privately disclosed a zero-click WeChat worm to Tencent.
BigBear phishing crew nets thousands of Microsoft 365 credentials
CloudSEC accessed the BigBear 2.0 phishing panel, finding 5,137 stolen Microsoft 365 records across 461 organizations, including 474 MFA-bypassed sessions.
CloudSEC researchers got inside the admin panel of BigBear 2.0, an Evilginx2-based phishing-as-a-service operation run by someone known as 'General Boss'. The panel contained 5,137 records tied to 461 organizations: 1,032 plaintext passwords and 4,148 session cookies, with 474 complete MFA-bypassed authentications. The adversary-in-the-middle proxy captures Microsoft 365 session cookies that can be replayed to access email, Teams, SharePoint, and OneDrive, potentially pivoting into Entra ID and federated SaaS. The operation was still active, used custom JavaScript to disable FIDO2/WebAuthn on phishing pages, and routed logins through a residential proxy pool spanning 69 countries.
BigBear 2 PhaaS Campaign Steals 5000+ Microsoft Credentials
CloudSEK researchers found the BigBear 2.0 PhaaS kit, built on Evilginx2, has stolen over 5,100 Microsoft 365 credentials across 461 organizations in 40+ countries.
CloudSEK gained admin access to the BigBear 2.0 phishing-as-a-service panel, an Evilginx2-based adversary-in-the-middle platform operated by someone using the alias 'General Boss'. The team observed 3,331 unique victim IPs across more than 40 countries, 42 VPS nodes mostly on Vultr, and 5,137 credential records across 461 organizations, including 4,148 session cookies, 1,032 plaintext passwords, and 474 completed MFA-bypassed authentications. IT and managed service providers were the most targeted sector, raising supply-chain risk since their compromise can expose client infrastructure and privileged Azure AD access.
BigBear 2.0 Evilginx2 Phishing Campaign Bypasses Microsoft 365 MFA With Session Cookie Theft
CloudSEK identified BigBear 2.0, an Evilginx2-based AiTM phishing operation stealing Microsoft 365 MFA session cookies, hitting 461 organizations across 40-plus countries.
The campaign proxies Microsoft sign-in pages to capture credentials and authenticated session cookies, enabling session replay into email, Teams, SharePoint, OneDrive, and connected SSO applications. CloudSEK's June 2026 discovery found 5,137 stolen records, 1,032 passwords, and 4,148 session cookies tied to 3,331 victim IPs, linked to operator 'General Boss' across 42 VPS nodes. The operation targeted IT services and managed service providers, used country-matched residential proxies, and involved at least five affiliates.
Fake IT Calls Target Executives in Microsoft 365 Data Theft and Extortion Attacks
Arctic Wolf tracks PREY-0058, a vishing and AitM token-theft crew targeting Microsoft 365 executives for data theft and extortion.
Arctic Wolf disclosed a widespread data theft and extortion cluster, PREY-0058, which overlaps with Mandiant's UNC6671 and possibly the Pink/Cinder extortion groups. Attackers impersonate IT help desk staff by phone, direct executives to authentication-themed lure domains, and run adversary-in-the-middle Microsoft 365 logins to harvest credentials, MFA approvals, and session tokens replayed via residential proxies such as NodeMaven. After access, they run discovery in SharePoint and Entra ID, then bulk-exfiltrate data from SharePoint, OneDrive, Exchange, and Box before sending extortion demands. Targets are primarily US construction, healthcare, real estate, finance, and professional services organizations.
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.
TrueConf Server Flaws Exploited to Replace Client Installers with PhantomCore
Head Mare exploits TrueConf server flaws to install web shells and deliver PhantomCore and PhantomGraph backdoors at Russian organizations.
Kaspersky detected July 2026 attacks by the threat actor Head Mare exploiting a vulnerability chain (KLCERT-26-057 and KLCERT-26-058) in unpatched TrueConf videoconferencing servers. The chain enables arbitrary code execution with SYSTEM privileges, deployment of a web shell at locale.php, and replacement of client installers with versions delivering the PhantomCore backdoor and PhantomGraph, which uses Microsoft OneDrive as C2. Targets span Russian instrumentation, electronics, transport, energy, IT, and software firms. Patches shipped in TrueConf Server 5.3.9, 5.4.9, and 5.5.5 on June 18, 2026.