ZeroHour
Product

Microsoft Teams

8 mentions in 7 days · 21 in 30 days · 21 total · first seen · last

Timeline

Update your firewall rules: Teams and Copilot are changing address

Microsoft is redirecting Microsoft 365 and Teams web users to new *.cloud.microsoft domains, requiring firewall and proxy rule updates by early October.

Starting September 2026, Microsoft is redirecting M365 web users to copilot.cloud.microsoft and Teams web users to teams.cloud.microsoft, announced via MessageCenter posts MC1465764 and MC1462915. All redirects should complete by early October 2026, with limited Teams exceptions possible until December 31, 2026. Microsoft advises reviewing client, proxy, firewall, and secure web gateway configurations, and suggests using TenantRestrictions to control personal Microsoft account access instead of blocking the new Copilot address.

CSO Online · 4d agoAdvisory

Microsoft fixes Teams, Outlook launch failures on ARM Windows PCs

Microsoft fixed in KB5124012 a bug stopping Teams and new Outlook from launching on ARM Windows 11 PCs.

Microsoft confirmed Teams and the new Outlook could fail to launch or crash on ARM-based Windows 11 24H2+ devices such as Surface Pro 11 after installing updates from August 11, 2026 (KB5121003), mainly on machines without Microsoft Store updates. The September 8, 2026 Patch Tuesday cumulative update KB5124012 resolved the issue. Updating the Auto Super Resolution Package had served as a temporary workaround.

BleepingComputer · 4d agoOther1

Hackers Use Blob URLs and Microsoft Teams to Create Phishing Pages Inside Victims’ Browsers

Barracuda details a phishing campaign using Microsoft Teams OAuth redirects and browser blob URLs to render local fake DocuSign login pages for credential theft.

Barracuda researchers identified an active phishing campaign that routes DocuSign-themed emails with calendar invites through a Microsoft OAuth endpoint and crafted redirects into Microsoft Teams, then renders a fake sign-in page via a browser-generated blob URL. Because the page is assembled locally in memory and can register service workers and run in a sandboxed iframe, URL-reputation checks largely see legitimate Microsoft domains. The goal is credential theft and account takeover, not a flaw in Teams itself.

Cyber Security Newsupdated · 4d agofirst · 5d agoPhishing & fraud in the wild 13 sources

Attackers call employees’ personal phones to break into Microsoft 365 accounts

Microsoft tracks vishing campaigns by Storm-3121 and Storm-3032 that impersonate IT staff, phish Microsoft 365 credentials, and steal cloud data.

Microsoft Security Research has tracked a campaign since May 2026 in which attackers call or text employees' personal phones posing as IT staff, using passkey/MFA/SSO lures to run adversary-in-the-middle phishing or device-code authentication flows. Attackers register their own MFA methods for durable persistence, abuse Microsoft Graph for tenant discovery, and download SharePoint, OneDrive, and Exchange data below 1,000 files or emails per hour to avoid detection. Microsoft attributes initial access to actors including Storm-3121, which feeds ShinyHunters and Falcon extortion operations, and Storm-3032, the Helix extortion operation descended from BlackFile.

Help Net Securityupdated · 4d agofirst · 5d agoPhishing & fraud in the wild 13 sources1

New Phishing Attack Uses Blob URLs to Hide Malicious Pages From Security Scanners

Barracuda detailed a DocuSign-themed phishing campaign that renders credential-harvesting pages as browser blob URLs, evading URL reputation and blocklist defenses.

Barracuda researchers report a credential-harvesting phishing campaign that starts with a DocuSign-themed email containing a calendar invitation and routes victims through legitimate Microsoft OAuth endpoints and Microsoft Teams. A crafted redirect parameter leads Teams to load external content from cdn.bloom[.]io, which the browser renders as a blob URL — a session-only address held in local memory with no persistent public URL to crawl, categorize, or blocklist. The locally generated page registers a service worker, runs inside a sandboxed iframe, and is dynamically steered by backend infrastructure, indicating a centrally managed phishing platform. Barracuda recommends phishing-resistant MFA such as FIDO2 keys and passkeys, monitoring OAuth flows and redirect chains, and Teams malicious URL protection.

GBHackersupdated · 4d agofirst · 5d agoPhishing & fraud in the wild 13 sources

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.

Cyber Security Newsupdated · 4d agofirst · 6d agoPhishing & fraud in the wild 13 sources

ChatGPT flaw lets attackers pull Gmail data across accounts via a hidden channel

Check Point found a ChatGPT flaw letting attackers read victims' Gmail and connected-app data via hidden cross-session instructions; OpenAI patched it.

Check Point Research discovered a covert cross-account command channel in ChatGPT's code execution environment, where containers meant to be isolated shared metadata through an internal service based on JFrog Artifactory. In a proof of concept, a victim's session was tricked into retrieving Gmail email data and relaying it to an attacker-controlled session during an ordinary-looking interaction, with reach extending to any connected apps the session was authorized for, including Google Drive, Microsoft Teams, and GitHub. OpenAI fixed the issue and decommissioned the internal service; the same shared infrastructure was also involved in the separately disclosed Hugging Face compromise, though via different techniques.

CSO Online · 6d agoAI safety & security 2 sources

New Phishing Attack Creates Malicious Pages Inside the Victim’s Browser

Barracuda details a phishing campaign that renders pages in-browser via blob URLs, routed through Microsoft Teams and cdn.bloom[.]io to evade detection.

Barracuda researchers analyzed a phishing campaign that generates a blob URL to render the phishing page entirely inside the victim's browser, leaving no static page for scanners to inspect. The chain begins with a Docusign-themed email containing a calendar invite, followed by a crafted redirect through Microsoft Teams to a resource on cdn.bloom[.]io that the browser converts into the blob URL. Service workers, iframes, and a hidden command-and-control configuration indicate the page is part of a centrally managed phishing platform that can be updated and steered across victims. Researchers recommend inspecting blob URL activity, monitoring OAuth authorization flows, and analyzing the full click path in email security controls.

SecurityWeekupdated · 4d agofirst · 6d agoPhishing & fraud in the wild 13 sources

Hackers Impersonate IT Support on Microsoft Teams to Take Control of Employee PCs

Microsoft warns of a human-operated campaign where attackers pose as IT support in Teams to gain remote PC control and reach domain controllers.

Microsoft Threat Intelligence observed attackers abusing Microsoft Teams external collaboration to impersonate IT/helpdesk staff, persuading employees to grant screen control via Quick Assist or RMM tools. Operators deploy malicious MSI packages via silent msiexec, run encrypted JavaScript implants through portable Node.js, and persist via EdgeUpdate Run keys or Startup folder entries. The Node.js backdoor uses HTTPS long-polling C2, captures screenshots, enumerates Active Directory, and moves laterally over WinRM (TCP 5985) to domain controllers and certificate authorities. Initial access maps to MITRE ATT&CK T1566.003 (Spearphishing via Service); no Teams vulnerability is exploited.

GBHackers · 7d agoPhishing & fraud in the wild

Week in review: Claude accounts compromised through infostealer, Patch Tuesday forecast

Help Net Security week-in-review roundup: Claude infostealer lockouts, record Patch Tuesday, McKesson breach, SonicWall zero-days, PaperCut attacks.

This Help Net Security weekly roundup aggregates prior stories: Anthropic locking out Claude users after infostealer-compromised login sessions, August 2026 Patch Tuesday's 398 resolved CVEs, ShinyHunters' claim of 284 million stolen patient records from McKesson, active exploitation of SonicWall SMA 1000 zero-days (CVE-2026-83548/83549), Sangoma Switchvox SQL injection exploitation (CVE-2026-9586), and attackers planting RATs on compromised PaperCut servers. It also covers FBI OAuth phishing warnings, a Spring Ring vishing campaign abusing Microsoft Teams, and a fake Claude Opus 5 GitHub repo delivering RevStealer infostealer.

Help Net Security · 9d agoOther in the wildCVE-2026-62911CVE-2026-83548CVE-2026-83549+1 CVEs1

Teams calls are about to get a lot harder to fake

Microsoft will roll out Brand Impersonation Protection in Teams Calling from mid-May 2026, warning users about suspicious inbound VoIP calls impersonating trusted brands.

Microsoft Teams Calling is gaining Brand Impersonation Protection, which evaluates inbound VoIP calls from first-time external callers for signs of brand impersonation and displays warnings before users answer high-risk calls. The feature rolls out from mid-May 2026 with completion expected by late May 2026, is enabled by default, and requires no administrative action. Users can accept, block, or end flagged calls, and alerts may continue throughout a call if suspicious activity persists. Microsoft recommends preparing helpdesk teams and updating security awareness materials ahead of deployment.

Help Net Security · 11d agoTools

Microsoft Teams is about to make QR code phishing much harder

Microsoft Teams will obscure QR codes from external senders starting October 2026, adding friction against QR-code phishing across Android, desktop, iOS, and Mac.

Microsoft 365 Roadmap entry 570439 describes a Teams feature that obscures images containing QR codes sent by external users, requiring users to reveal them before viewing or scanning. Rollout is expected to begin in October 2026 for Android, desktop, iOS, and Mac. The feature aims to reduce QR code phishing risk, which NordVPN says has redirected more than 26 million users to malicious websites, with 73% of Americans scanning codes without verifying destinations.

Help Net Security · 11d agoTools1

ThreatsDay: CEO Phishing Kits, 5K Dropbox Account Hacks, OAuth Traps + 17 More Stories

Microsoft warns of Teams IT-impersonation intrusions deploying Node.js implants; Spring Ring vishing hit 150+ employees across 10 companies; The Gentlemen ransomware claims 683 victims.

Microsoft warned of a human-operated campaign abusing Teams external collaboration to impersonate IT help desk staff, deploy malicious MSI packages staging Node.js runtimes and obfuscated JavaScript implants, then pivot to domain controllers over WinRM. Unit 42 documented the Spring Ring vishing operation targeting over 150 employees across at least 10 companies using 26 attacker identities, including an NTLM relay variant against domain controllers. Sophos reported The Gentlemen ransomware (Gold Sherwood) reached 683 total victims by end of July 2026, adding 169 in July, with a playbook using BYOVD-based EDR killers and backup tampering. Group-IB found the Outsider phishing-as-a-service platform created 700+ new phishing pages within a month despite law enforcement takedowns.

The Hacker News · 12d agoThreat actor in the wild1

Impersonating IT support: how threat actors turn a remote session into enterprise-wide access

Microsoft details Teams IT-support impersonation campaigns deploying Node.js implants, AD reconnaissance, and WinRM lateral movement toward domain controllers.

Microsoft Threat Intelligence describes a human-operated campaign where attackers impersonate IT/helpdesk staff via Microsoft Teams external collaboration, talk users into granting remote sessions, and use RMM tools for interactive access. During the session they run PowerShell to silently install a malicious MSI that stages a portable Node.js runtime and obfuscated JavaScript implant for C2, executing follow-on payloads via rundll32. Operators then perform host and Active Directory reconnaissance, capture desktop screenshots, and pivot via WinRM on port 5985 to domain controllers and certificate authorities. The hands-on-keyboard chain, which can precede data theft and ransomware, blends into normal operations by relying on Teams, Quick Assist, msiexec, and Node.js; Microsoft shares hunting and mitigation guidance.

Microsoft Security Blog · 12d agoThreat actor in the wild

Threat Gang 'Springs' Vishing Attacks on Microsoft Teams Users

The 'Spring Ring' operation uses vishing attacks against Microsoft Teams users to hijack sessions, deploy malware, and take over infrastructure.

Dark Reading reports on the Spring Ring threat gang conducting voice-phishing (vishing) attacks against users of Microsoft Teams. The operation aims to compromise collaboration-suite accounts to gain remote access to victim sessions, distribute malware, and potentially seize control of infrastructure. Further technical details were not provided in the available text.

Dark Reading · 13d agoPhishing & fraud

Vishing campaign abuses Microsoft Teams to give attackers a foothold in company networks

Unit 42 details 'Spring Ring', a vishing campaign using fake IT support on Microsoft Teams to reach 150+ employees at 10+ companies.

Palo Alto Networks Unit 42 documented 'Spring Ring', a voice-phishing campaign that ran January to April 2026, using 26 attacker identities and fake Microsoft 365 tenants such as 'ITProtectionDepartment' to impersonate internal IT support on Microsoft Teams. One path used Quick Assist or downloaded remote-support tools to run an obfuscated PowerShell script that disabled malware scanning before contacting C2; the other delivered a cloud-hosted file triggering browser hijacking, SMB internal network scanning, and a PetitPotam NTLM relay attempt against domain controllers to gain domain-level privileges. Both intrusion attempts were blocked before attackers reached their objectives. Collaboration-platform phishing alerts rose to 42% of Unit 42's telemetry in early 2026, up from 30%.

Help Net Security · 14d agoPhishing & fraud in the wild

Spring Ring: An Inside Look at Voice Phishing Campaigns in Microsoft Teams

Unit 42 details the Spring Ring voice phishing campaign abusing Microsoft Teams to deploy malware and target enterprise domain controllers.

Palo Alto Networks Unit 42 analyzed the Spring Ring campaign, which abuses Microsoft Teams and voice phishing (vishing) to compromise enterprise users. Attackers use Teams calls to social-engineer victims, then deploy malware and advance toward enterprise domain controllers. The report documents the campaign's tactics and provides detection guidance for defenders.

Palo Alto Unit 42 · 15d agoPhishing & fraud in the wild

Microsoft Teams Has Become a Haven for Scammers in China

Scammers in China are exploiting Microsoft Teams and Webex to trick Chinese victims into transferring large sums of money.

WIRED reports that fraudsters are abusing enterprise chat platforms including Microsoft Teams and Cisco Webex to run scams against victims in China. Victims are socially engineered into transferring large sums of money. The campaign has generated a wave of complaints, highlighting how scam groups abuse legitimate business communication tools.

WIRED · Security · 18d agoPhishing & fraud in the wild

WordlistLoader Delivers Amatera via ClickFix, SynkLoader Phishes Windows Passwords

Gen Digital details WordlistLoader delivering Amatera Stealer via ClickFix and EtherHiding, while SynkLoader phishes Windows credentials through Microsoft Teams.

Gen Digital identified WordlistLoader, an intermediate stage that reconstructs shellcode encoded as plain English words (or 16-byte UUID chunks) and loads Amatera Stealer 4.3.3-alpha1, delivered through ClearFake ClickFix prompts on compromised websites. The chain uses EtherHiding to fetch JavaScript from a blockchain smart contract, hidden cmd.exe via conhost, WebDAV-mounted shares with rundll32 execution, and ETW bypass via hardware breakpoints. The stealer adds hardened WoW64 syscalls, Heaven's Gate indirect-syscall trampolines and a redesigned application-bound encryption bypass. Separately, Expel observed SynkLoader distributed via Microsoft Teams phishing impersonating IT service desks, installing an MSI from Azure blob storage and serving a fake lock screen to capture credentials.

The Hacker News · 20d agoMalware

TWINLOOT Abuses SharePoint and Teams to Steal Credentials and Move Across Networks

Ontinue disclosed TWINLOOT, a Python implant hiding C2 in SharePoint dead drops and Teams TURN relays, harvesting credentials and pivoting via reverse SOCKS5.

Ontinue's Cyber Defense Center identified TWINLOOT during a July 2026 campaign investigation: a modular, PyArmor-hardened Python implant (a 39 MB bootstrap-fat.pyc loader) whose entire C2 infrastructure lives inside trusted Microsoft services. Tasking flows through SharePoint Online file dead drops polled every 15 seconds via the Microsoft Graph API, while interactive operator access uses WebRTC DataChannels relayed by Microsoft Teams TURN servers; Graph traffic is driven by the victim's own headless Edge browser. The implant harvests Windows credentials with fake lock screens, offers a reverse SOCKS5 pivot for lateral movement to SMB, RDP, WinRM, and MSSQL, executes commands, and persists on hosts. Initial access is assessed to be Teams social engineering masquerading as IT support, prompting a PowerShell command to download the payload.

The Hacker News · 28d agoMalware

DragonForce Hackers Abuse Microsoft Teams Relays to Hide Backdoor.Turn C2 Traffic

Symantec and Carbon Black found DragonForce-linked hackers using Backdoor.Turn, a Go RAT tunneling C2 through Microsoft Teams TURN relays via QUIC.

Broadcom's Symantec and Carbon Black documented Backdoor.Turn, a Go-based RAT associated with the DragonForce ransomware group, deployed at a major U.S. services firm where attackers remained on the network for one to two months. The backdoor obtains an anonymous Teams visitor token from Microsoft's Skype-backed identity services, uses a legitimate Microsoft TURN relay for connection setup, and runs a QUIC session to the attacker's C2 server, so defenders see only outbound traffic to legitimate Teams servers. Initial access is suspected to involve exploiting a SQL/MS-SQL vulnerability or an access broker, followed by a PowerShell-dropped ZIP, DLL side-loading, and BYOVD evasion using a Huawei driver; the RAT is injected into DbgView64.exe after DragonForce ransomware deployment for continued access. First publicly documented TURN abuse by the group, it leverages Praetorian's Ghost Calls technique and supports command execution, network scanning, LDAP/AD search, lateral movement, and browser credential theft.

Related CVEs

  • Pre-Authentication SSRF in SonicWall SMA1000 Appliance Workplace Interface
    CVE-2026-83548 is a critical (CVSS 3.1 score 10.0) server-side request forgery (SSRF) vulnerability in the Workplace interface of SonicWall SMA1000 appliances, caused by an unintended alternate access path (unprotected alternate channel, CWE-441; SSRF, CWE-918). Because it is pre-authentication, any remote unauthenticated attacker who can reach the interface can trigger it and gain unauthorized access to sensitive functionality and perform unauthorized operations. CISA lists all SonicWall SMA1000 appliances as affected, with CPE data naming the SMA 8200v and SMA 6210/7210 firmware; internet-exposed units are at highest risk. The flaw is being actively exploited in the wild: it was added to CISA's Known Exploited Vulnerabilities catalog on 2026-09-02 alongside companion zero-day CVE-2026-83549, which reporting suggests may form an attack chain with this SSRF. Exploitation probability is elevated (EPSS 4.7%, 91st percentile) and no public proof-of-concept is known.
    · SonicWall SMA1000 appliance Workplace interface · SonicWall SMA 8200v KEVmoderate
  • Unauthenticated SQL Injection RCE in Sangoma Switchvox SMB Edition
    Sangoma Switchvox SMB Edition 8.3 (build 104997) contains an unauthenticated SQL injection flaw (CWE-89) in its /pa endpoint, where the user-controlled PhoneIP value from XML input is concatenated directly into PostgreSQL queries without sanitization or parameterization. A single crafted request lets a remote, unauthenticated attacker execute arbitrary SQL statements against the backend PostgreSQL database, which can be escalated to remote code execution on the server. Any organization running the affected Switchvox SMB Edition build is exposed, especially appliances reachable from the internet. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV catalog on 2026-09-02, and researchers have observed attackers using it without credentials to deploy reverse shells and cryptocurrency miners.
    · Sangoma Switchvox SMB Edition 8.3 (build 104997) KEV PoC moderate
  • Authenticated OS Command Injection RCE in SonicWall SMA1000 Appliance Console
    CVE-2026-83549 is a post-authentication OS command injection flaw (CWE-78) in the Appliance Management Console (AMC) of SonicWall SMA1000 appliances. An attacker who authenticates to the AMC with administrator privileges can, under specific conditions, inject arbitrary operating system commands and achieve remote code execution on the appliance. Only organizations running SMA1000-series appliances, including the SMA 6210, SMA 7210, and SMA 8200v models cited in the data, are affected. CISA added the flaw to the KEV catalog on 2026-09-02, and news reports describe active exploitation, possibly chained with companion zero-day CVE-2026-83548, with reverse shells and cryptocurrency miners observed; no public proof-of-concept is known. EPSS assigns an 8.5% probability of exploitation within 30 days (95th percentile).
    · SonicWall SMA1000 series appliances - Appliance Management Console (AMC) · SonicWall SMA 6210 (SMA1000 series firmware) KEVmoderate
  • Capture-Replay Authentication Bypass in Microsoft Exchange Server
    Microsoft Exchange Server contains an authentication bypass flaw (CWE-294) in which captured authentication material can be replayed, allowing an authorized attacker to elevate privileges over a network. Per the CVSS vector, the attack is network-based with low complexity but requires the attacker to already hold low privileges and some user interaction, and success yields high impact on confidentiality, integrity, and availability. Affected products include on-premises Exchange Server and Exchange Server Subscription Edition, though specific vulnerable version ranges are not specified in the available data. Public scans indicate nearly 22,000 Exchange servers remain exposed to the flaw following the August 2026 Patch Tuesday fixes. No in-the-wild exploitation, public proof-of-concept, or KEV listing is known; the bug was demonstrated at Pwn2Own (ZDI-26-534) and carries an EPSS estimate of 1.3% probability of exploitation within 30 days.
    · microsoft exchange server · microsoft exchange server subscription editionlarge
  • The wsftprm.sys kernel driver 2.0.0.0 in Topaz Antifraud allows low-privileged attackers to kill any (Protected Process Light) process via an IOCTL (which will
    The wsftprm.sys kernel driver 2.0.0.0 in Topaz Antifraud allows low-privileged attackers to kill any (Protected Process Light) process via an IOCTL (which will be named at a later time).
    · topazevolution antifraud PoC
  • A vulnerability in the K7RKScan.sys driver, part of the K7 Security Anti-Malware suite, allows a local low-privilege user to send crafted IOCTL requests to term
    A vulnerability in the K7RKScan.sys driver, part of the K7 Security Anti-Malware suite, allows a local low-privilege user to send crafted IOCTL requests to terminate a wide range of processes running with administrative or system-level privileges, with the exception of those inherently protected by the operating system. This flaw stems from missing access control in the driver's IOCTL handler, enabling unprivileged users to perform privileged actions in kernel space. Successful exploitation can lead to denial of service by disrupting critical services or privileged applications.
  • The GameDriverX64.sys kernel-mode anti-cheat driver (v7.23.4.7 and earlier) contains an access control vulnerability in one of its IOCTL handlers.
    The GameDriverX64.sys kernel-mode anti-cheat driver (v7.23.4.7 and earlier) contains an access control vulnerability in one of its IOCTL handlers. A user-mode process can open a handle to the driver device and send specially crafted IOCTL requests. These requests are executed in kernel-mode context without proper authentication or access validation, allowing the attacker to terminate arbitrary processes, including critical system and security services, without requiring administrative privileges.

Appears with

Entities are extracted by the model from each article. Watching an entity keeps it in this browser only (no account); the watchlist page and dashboard alerts use it.