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Last updated: May 13, 2026 at 5:42 AM UTC
All 208 Vulnerability 72 Breach 41 Threat 88 Defense 7
Tag: mfa-bypass (6 articles)Clear

Iranian hackers used Microsoft Teams chat to social-engineer victims, then dressed up their espionage as a Chaos ransomware attack to throw off blame

Rapid7 disclosed an Iranian state-sponsored intrusion that disguised itself as a Chaos ransomware attack to mask the real goal: cyber-espionage. The threat actor (assessed with moderate confidence as MuddyWater, linked to Iran's Ministry of Intelligence and Security) initiated chat requests through Microsoft Teams, walked employees into screen-sharing sessions, then captured credentials and manipulated MFA prompts. Some victims were asked to type their passwords into local text files during the call. Persistence came from a custom backdoor (Game.exe) deployed alongside DWAgent, AnyDesk, and RDP. The fake ransomware note and Chaos leak-portal entry concealed the espionage.

Check
Search Microsoft Teams logs for external chat invitations from unknown Entra tenants since January. Hunt endpoints for DWAgent, AnyDesk, ms_upd.exe, or Game.exe processes installed without IT approval.
Affected
Organizations allowing external Microsoft Teams chats by default - the campaign starts with chat invitations from attacker-controlled tenants. Acute risk for sectors MuddyWater historically targets: government, defense, telecoms, energy, and Israeli organizations. The 'IT Support' impersonation pattern works against any helpdesk-heavy enterprise. Iranian APT activity has been increasing through early 2026.
Fix
Restrict external Microsoft Teams chat to allowlisted partner tenants only. Block external screen-sharing requests by default. Brief staff that real IT support never asks them to type passwords into local files or read out MFA codes during a Teams call. Block Rapid7's published Stagecomp/Darkcomp code-signing certificate at the EDR layer.

Microsoft says fake HR compliance emails fooled 35,000 people across 26 countries - phishing kit captured login tokens even with MFA enabled

Microsoft disclosed Monday that a phishing campaign between April 14 and 16 hit 35,000+ users across 13,000+ organizations in 26 countries (92% in the US). Lures impersonated internal HR with subjects like 'Internal case log issued under conduct policy.' Each email had a PDF attachment with a 'Review Case Materials' link that walked victims through Cloudflare CAPTCHAs and a final adversary-in-the-middle (AiTM) Microsoft sign-in page. AiTM proxies the real Microsoft login and captures session tokens after MFA - so traditional MFA is bypassed. Healthcare (19%), financial services (18%), and professional services (11%) were the most-targeted sectors.

Check
Search Exchange Online logs for emails between April 14-16 with subjects containing 'conduct policy' or 'awareness case log.' Hunt sign-in logs for OAuth grants from acceptable-use-policy-calendly.de or compliance-protectionoutlook.de.
Affected
Microsoft 365 / Entra ID tenants with users on traditional MFA (push, SMS, TOTP). AiTM bypasses any non-phishing-resistant MFA factor - only FIDO2 hardware keys and Windows Hello are immune. US users in healthcare, life sciences, financial services, and professional services are at acute risk based on Microsoft's targeting data.
Fix
Migrate users to phishing-resistant MFA (FIDO2 hardware keys, Windows Hello, passkeys) for all accounts. Enable Conditional Access policies that require token binding for high-privilege accounts. Turn on Zero-hour auto purge in Defender for Office 365 to retroactively quarantine campaign emails. Revoke session tokens for any user who visited a fake sign-in page.

New 'ConsentFix v3' attack lets criminals take over Microsoft 365 accounts even when MFA and passkeys are turned on

Push Security disclosed ConsentFix v3, a new attack that lets criminals take over Microsoft 365 accounts even if the victim has MFA and phishing-resistant passkeys turned on. The trick: instead of stealing a password, the attacker tricks the user into pasting a Microsoft authorization URL into a phishing page during what looks like a routine login. That URL contains a one-time code that the attacker exchanges for permanent access tokens. v3 automates the whole attack with Cloudflare Pages phishing sites, Pipedream webhook automation, and tenant fingerprinting that customizes the lure to each target organization's branding.

Check
Brief any Microsoft 365 admin or developer that any 'verification step' that asks them to paste a URL containing 'localhost' into a webpage is hostile, no matter how legitimate the page looks.
Affected
Any Microsoft 365 / Entra ID tenant. The attack bypasses MFA, passkeys, and most Conditional Access policies by abusing pre-consented Microsoft first-party apps. Acute risk for organizations whose admins, developers, or DevOps engineers regularly use Azure CLI - those users won't suspect a fake Azure CLI authorization page. Cloudflare Pages and Pipedream both look legitimate in network telemetry.
Fix
Apply token binding to trusted devices and require Conditional Access for first-party Microsoft apps where possible. Hunt Azure sign-in logs for Azure CLI authentications from unfamiliar IPs, especially against accounts that don't normally use it. Train developers to verify out-of-band any 'verification step' that asks them to paste URLs into a webpage. Use app authentication restrictions to limit which first-party apps can issue refresh tokens.

FBI and Indonesian police dismantle W3LL phishing platform that powered business email compromise attacks worldwide

The FBI Atlanta Field Office and Indonesian authorities have dismantled the W3LL global phishing platform and arrested its alleged developer. W3LL sold a sophisticated phishing kit designed specifically for bypassing multi-factor authentication on Microsoft 365 accounts using adversary-in-the-middle (AiTM) techniques. The platform operated as a phishing-as-a-service ecosystem with its own marketplace, support channels, and licensing model, enabling thousands of business email compromise campaigns targeting corporate Microsoft 365 environments. This is described as the first coordinated international law enforcement action against this platform. Group-IB previously estimated W3LL's tools had been used to compromise over 8,000 Microsoft 365 business accounts.

Check
Review your Microsoft 365 security configuration. W3LL's kit was specifically designed to bypass standard MFA on M365 - organizations relying solely on push notification or SMS-based MFA for M365 were the primary targets.
Affected
Organizations using Microsoft 365 with standard MFA (push notifications, SMS codes, or authenticator app approval prompts). W3LL's AiTM technique proxied real login pages to intercept session tokens after MFA completion.
Fix
Deploy phishing-resistant MFA for Microsoft 365 - FIDO2 security keys or Windows Hello for Business are resistant to AiTM attacks. Enable conditional access policies that evaluate sign-in risk, device compliance, and location. Monitor for suspicious mailbox rules (forwarding, deletion rules) which are the first post-compromise action in BEC campaigns. The W3LL takedown disrupts one platform, but the AiTM phishing technique is now widely adopted by other kits.

EvilTokens phishing kit commoditizes Microsoft device code attacks for business email compromise

A new phishing-as-a-service kit called EvilTokens is being sold on Telegram, turning OAuth device code phishing against Microsoft accounts into a turnkey attack. Victims receive emails with PDFs or HTML files containing QR codes or links to pages impersonating Adobe, DocuSign, or SharePoint. The kit captures Microsoft authentication tokens in real time - bypassing MFA - and gives attackers persistent access for business email compromise. The developer says Gmail and Okta support is coming next.

Check
Review your Microsoft Entra ID logs for unusual device code authentication flows, especially from unfamiliar locations or devices.
Affected
Any organization using Microsoft 365 with users who may click on phishing emails disguised as document-sharing notifications.
Fix
Restrict or disable the device code authentication flow in Microsoft Entra ID conditional access policies if your organization doesn't need it. Deploy phishing-resistant MFA (FIDO2 hardware keys). Train finance, HR, and sales teams to recognize fake document verification pages. Monitor for anomalous token grants in Entra ID sign-in logs.

TikTok for Business accounts targeted with AITM phishing that bypasses MFA

A new phishing campaign is hijacking TikTok for Business accounts using adversary-in-the-middle (AITM) reverse proxy pages - meaning it captures credentials, session cookies, and MFA codes in real time. Victims land on cloned TikTok or Google Careers pages after clicking links that redirect through legitimate Google Storage URLs. The real kicker: most users log in via Google SSO, so one compromise gives attackers both TikTok and Google accounts.

Check
Alert marketing and social media teams who manage TikTok Business accounts.
Affected
Any TikTok for Business account, especially those using Google SSO for login.
Fix
Use hardware security keys (FIDO2) instead of SMS/app-based MFA - AITM kits can't intercept them. Review TikTok account sessions for unauthorized access. Train staff to verify URLs before entering credentials.