All news with #microsoft tag

🔒 Microsoft has updated File Explorer to disable the preview pane by default for files downloaded from the Internet or marked with the Mark of the Web. The change, included in Windows security updates released on and after October 14, 2025, is designed to block exploits that can leak NTLM hashes when previewed documents reference external resources. When preview is blocked, File Explorer shows a warning and users can manually unblock trusted files via Properties > Unblock or add the location to Trusted sites/Local intranet; a sign-out may be required for the change to take effect.

🛡️ Microsoft said it disrupted a ransomware campaign that used fake Teams installers to deliver a backdoor and prepare for encryption operations. Attackers lured victims with impersonated MSTeamsSetup.exe files hosted on malicious domains, which installed a loader and a fraudulently signed Oyster backdoor. The group identified as Vanilla Tempest intended to follow with Rhysida ransomware. Microsoft revoked over 200 fraudulent code-signing certificates and says a fully enabled Defender Antivirus will block the threat.

🛡️ Cisco Talos Incident Response observed a surge in attacks exploiting public-facing apps in Q3 2025, driven chiefly by ToolShell chains targeting on-premises Microsoft SharePoint servers. Rapid automated scanning and unauthenticated RCE vulnerabilities led to widespread compromise, highlighting the need for immediate patching and strict network segmentation. Post-compromise phishing from valid accounts and diverse ransomware families, including Warlock and LockBit, continued to impact victims.

🔒Researchers detail a threat cluster called Jingle Thief that leverages phishing and smishing to harvest credentials and compromise cloud environments of retailers and consumer services to issue unauthorized gift cards. Palo Alto Networks Unit 42 links the activity to financially motivated actors and notes coordinated campaigns in April-May 2025. The attackers favor identity misuse over malware, persistently mapping tenants, abusing Microsoft 365 services, and minimizing logs to sustain large-scale fraud.

🔒 The Microsoft Digital Defense Report 2025 warns that cyber threats are accelerating in speed, scale, and sophistication, driven by AI and coordinated, cross-border operations. Attack windows have shrunk—compromises can occur within 48 hours in cloud containers—while AI-powered phishing and credential theft have grown markedly more effective. For CISOs this requires reframing security as a business enabler, prioritizing resilience, automation, and modern identity controls such as phishing-resistant MFA. The Secure Future Initiative provides practitioner-tested patterns to operationalize these priorities.

🔒 Symantec reports that China-linked threat actors exploited the ToolShell vulnerability in Microsoft SharePoint (CVE-2025-53770) weeks after Microsoft issued a July 2025 patch, compromising a Middle Eastern telecom and multiple government and corporate targets across regions. Attackers used loaders and backdoors such as KrustyLoader, ShadowPad and Zingdoor, and in several incidents employed DLL side-loading and privilege escalation via CVE-2021-36942. Symantec notes the operations aimed at credential theft, stealthy persistence, and likely espionage, with activity linked to groups including Linen Typhoon, Violet Typhoon, Storm-2603 and Salt Typhoon.

🔎 Cyber asset attack surface management (CAASM) and external ASM (EASM) solutions help organizations discover and continuously monitor internet-facing assets to reduce exposure and harden security. The article surveys a dozen commercial offerings — including Axonius, CrowdStrike Falcon Exposure, Microsoft Defender EASM, and Palo Alto Cortex Xpanse — highlighting discovery methods, integrations, AI features, and sample pricing. It stresses continuous monitoring, asset context and prioritization, and recommends vetting vendor automation, remediation workflows, and pricing transparency.

🔒 Microsoft confirmed that Windows updates released on and after August 29, 2025 enforce additional SID checks that can break Kerberos and NTLM authentication on devices with duplicate Security Identifiers (SIDs). Affected systems — including Windows 11 24H2, Windows 11 25H2, and Windows Server 2025 — may experience failed Remote Desktop sessions, SEC_E_NO_CREDENTIALS event errors, and "access denied" messages. The fault commonly arises when images are duplicated without using Sysprep. Microsoft recommends rebuilding impacted machines with supported imaging procedures or obtaining a temporary Group Policy from Support as an interim measure.

🔐 Microsoft Security Store, released to public preview on September 30, 2025, is a unified, AI-powered marketplace that lets organizations discover, buy, and deploy vetted security solutions and AI agents. Catalog items — organized by frameworks like NIST and by integration with products such as Microsoft Defender, Sentinel, Entra, and Purview — address threat protection, identity, compliance, and cloud security. Built on the Microsoft Marketplace, it provides unified billing, MACC eligibility, and guided automated provisioning to streamline deployments.

🔁 Microsoft positions the signals loop — continuous capture of user interactions and telemetry with systematic fine‑tuning — as essential for building adaptive, reliable AI apps and agents. The post explains that simple RAG and prompting approaches often lack the accuracy and engagement needed for complex use cases, and that continuous learning drives sustained improvements. It highlights Dragon Copilot and GitHub Copilot as examples where telemetry‑driven fine‑tuning yielded substantial performance and experience gains, and presents Azure AI Foundry as a unified platform to operationalize these feedback loops at scale.

🛠️ Microsoft has implemented a fix for a major issue that prevented some Microsoft 365 customers from launching the classic Outlook client on Windows. Affected users reported errors indicating the app could not be started, the Outlook window would not open, or Exchange sign-in failed. Microsoft marked the incident as fixed and said the Outlook team is monitoring the rollout, while recommending Outlook Web Access or the new Outlook for Windows as temporary workarounds.

🚨 The October 2025 Windows security update KB5066835, intended to move cryptography from CSP to KSP, is causing widespread enterprise disruption. Affected platforms — including Windows 10 (22H2), Windows 11 (23H2–25H2) and several Windows Server releases — report smartcard and certificate failures, USB mouse/keyboard loss in WinRE, IIS ERR_CONNECTION_RESET and WUSA installation errors. Microsoft published a registry workaround (DisableCapiOverrideForRSA=0) and an out‑of‑band update (KB5070773) for some issues, but urges caution and recommends thorough testing before broad deployment.

⚠ After installing the October 14, 2025 security update KB5066835, USB-wired mice and keyboards do not function in the Windows Recovery Environment (WinRE), Microsoft confirmed. The devices continue to operate normally inside the Windows OS, but WinRE navigation is blocked, affecting Windows 11 (24H2, 25H2) and Windows Server 2025. Microsoft is working on a fix expected in the coming days; meanwhile users can rely on Bluetooth peripherals or legacy PS/2 input devices as a workaround.

🔒 CISA warns that threat actors are actively exploiting a high-severity Windows SMB vulnerability tracked as CVE-2025-33073, which can allow elevation to SYSTEM on unpatched machines. Microsoft patched the flaw in its June 2025 Patch Tuesday release, citing an improper access control weakness that can be abused over a network. The bug affects Windows Server, Windows 10 and Windows 11 up to 24H2. Federal agencies must remediate within three weeks under BOD 22-01, and all organizations are urged to apply the update immediately.

🔒 Microsoft warns the October 2025 Windows security updates are causing smart card authentication and certificate failures by switching RSA-based smart card certificates to use KSP instead of CSP. Affected systems may report errors such as "invalid provider type specified" or "CryptAcquireCertificatePrivateKey error" and Event ID 624 in the Smart Card Service log. Microsoft provides a manual workaround: set the DisableCapiOverrideForRSA registry value to 0, back up the registry first, then restart. This impacts Windows 10, Windows 11 and Windows Server releases; the company says the key will be removed in April 2026 and urges customers to work with application vendors to resolve compatibility.

🔍 Matt Kiely of Huntress Labs urges Microsoft 365 administrators to audit OAuth applications across their tenants and provides a pragmatic starting tool, Cazadora. The research shows both abused legitimate apps (Traitorware) and bespoke malicious apps (Stealthware) can persist for years and that Azure’s default user-consent model enables these abuses. Operators should check Enterprise Applications and Application Registrations for suspicious names, anomalous reply URLs (notably a localhost loopback with port 7823), and other anomalous attributes, then take remediation steps.

🔒 A foreign threat actor exploited unpatched Microsoft SharePoint vulnerabilities to infiltrate the Kansas City National Security Campus (KCNSC), which produces most non‑nuclear components for U.S. nuclear weapons. Honeywell FM&T, which manages the site for the NNSA, and the Department of Energy did not respond to requests for comment. Federal responders, including the NSA, were onsite in early August after Microsoft issued fixes on July 19. Attribution remains disputed between Chinese-linked groups and possible Russian actors; there is no public evidence that classified information was taken.

✅ Microsoft removed two safeguard holds blocking Windows 11 24H2 installs. The April hold affecting systems using SenseShield's sprotect.sys driver—which could trigger BSODs—was lifted after a security.sys driver update; the feature update will be offered within 48 hours. The September 2024 hold for wallpaper customization apps that caused display and virtual-desktop issues was removed on October 15, 2025; affected devices may see a warning and must confirm before upgrading. Microsoft advises updating or uninstalling problematic apps or contacting their developers for support.

🔒 Microsoft patched a critical HTTP request smuggling vulnerability (CVE-2025-55315) in the Kestrel ASP.NET Core web server, which Microsoft described as the highest-severity ASP.NET Core flaw ever. An authenticated attacker could smuggle an additional HTTP request to hijack other users' credentials, bypass front-end security controls, or impact integrity and availability. Microsoft released updates for Visual Studio 2022, ASP.NET Core 2.3, 8.0 and 9.0 and advised developers to apply updates, recompile where required, and restart or redeploy affected applications.

🔧 Microsoft has fixed a known issue that broke HTTP/2 connections to localhost (127.0.0.1) and caused IIS sites to fail after recent Windows security updates. Affected systems included Windows 11 and Windows Server 2025, producing errors like “ERR_CONNECTION_RESET” and “ERR_HTTP2_PROTOCOL_ERROR”. Microsoft recommends checking Windows Update and restarting; it also enabled a Known Issue Rollback (KIR) for most home and non-managed devices, while enterprise admins can deploy a KIR group policy until a permanent update ships.