Topic
Microsoft Defender
Attackers Abuse Legitimate Microsoft Defender Exclusions to Conceal Malware
Malware & Botnets
BigDiskBuster Exploit Blocks Microsoft Defender Updates on All Supported Windows Versions
Vulnerabilities & Exploits
Group-IB Uncovers HEAVYGRAM Multi-Stage Windows Spyware Controlled via Telegram Bot API
Malware & BotnetsMicrosoft Defender Misclassifies Legitimate Google Search Links as Threats
Microsoft is investigating a false positive issue in Defender for Office 365 where legitimate Google search result links are incorrectly flagged as unsafe. Users attempting to open these links receive a warning stating the website may be insecure, and the problem persists even when copying and pasting URLs directly into browsers. The incident, tracked under advisory MO1465962, stems from erroneous classification by the Safe Links feature, which rewrites and rechecks URLs in email, Teams, and Microsoft 365 applications. The misclassification affects not only end users but also generates alerts for administrators in the Microsoft Defender Portal and Microsoft Sentinel SIEM platform. Safe Links is designed to protect against phishing by validating links at click time, but in this case it overreacted by blocking entire Google search URLs. Microsoft has not disclosed the number of impacted customers or affected regions and continues working on a fix for the erroneous classification.
Microsoft Defender Displays False 'Enable Virus Protection' Alerts on Windows Despite Active Real-Time Protection
Microsoft has confirmed a bug in Microsoft Defender that causes Windows to show persistent notifications urging users to enable virus protection even when the antivirus is already running with real-time protection active. The issue emerged after recent Defender updates and affects home users as well as enterprise environments running Windows 11 versions 23H2, 24H2, and 25H2, along with Windows 10 and Windows Server editions. Notifications appear at startup or during normal operation, ignore Do Not Disturb settings, and clicking them only opens the Windows Security app without resolving the alert. Microsoft is developing a fix to be released in a future Defender update but has not provided a timeline. Users are advised not to dismiss all such banners automatically, as similar messages could originate from malware, and should verify protection status through Windows Security or PowerShell commands. The problem stems from configuration errors introduced by the antivirus updates rather than specific Windows builds.
Microsoft Defender Zero-Day ShieldBreak Enables SYSTEM Privilege Escalation, Bypassing July Rogue Planet Patch
Security researcher Nightmare Eclipse has publicly disclosed a new zero-day vulnerability named ShieldBreak in Microsoft Defender that allows any standard Windows account to escalate privileges directly to SYSTEM level. The flaw exploits a TOCTOU race condition in Defender's file scanning API callbacks, enabling attackers to swap file contents during the brief window when the scanner reads the file. Although linked to the earlier Rogue Planet vulnerability (CVE-2026-50656), the July patch did not fully address the attack surface, and an adjusted proof-of-concept continues to work on patched systems. Defender's high privileges and trusted status in enterprise environments amplify the risk, as compromised processes can execute malicious actions that appear legitimate in logs. Public disclosure without prior private reporting leaves a window of exposure until Microsoft issues an official fix. Blue teams are advised to enforce strict local permissions, monitor for anomalous Defender process behavior such as unusual child processes or repeated file handle operations, and implement layered defenses including application whitelisting and network segmentation.
Microsoft Removes WMIC from Windows 11 After Years of Abuse as LOLBIN by Ransomware and Attackers
Microsoft has begun permanently removing the legacy WMIC command-line utility from Windows 11, starting with versions 24H2 and 25H2. The tool is no longer available in fresh installations, has been dropped as an optional component, and is absent from the latest beta builds. WMIC provided text-based access to Windows Management Instrumentation for querying hardware, processes, services, and security software, as well as performing administrative tasks. Although the underlying WMI technology remains untouched, Microsoft has deprecated the command shell due to its long-standing use as a LOLBIN in cyberattacks. Ransomware operators have leveraged WMIC to delete shadow copies and hinder recovery, while other attackers used it to enumerate and disable security tools or add exclusions in Microsoft Defender. Administrators are directed to migrate to PowerShell, COM API, .NET libraries, and modern scripting languages, which will require rewriting legacy automation scripts.
Weekly Roundup Highlights Critical Vulnerabilities in Zoom, nginx, SonicWall, and Microsoft Products
Security NEXT published its weekly ranking of the most-read articles for the period of July 12 to July 18, 2026. The top story covered a serious vulnerability in the Windows version of Zoom that has already been fixed in the latest release. Other high-ranking items included a cyber attack that disrupted operations at Nichirei and affected frozen food shipments, as well as Microsoft’s monthly security update addressing more than 500 vulnerabilities including zero-days. Additional widely read reports detailed multiple flaws in nginx, a zero-day issue affecting SonicWall SMA1000 series appliances, and a data exposure investigation involving a TV Asahi subsidiary. The list also featured advisories on GNU Wget SSRF flaws, privilege escalation bugs in Microsoft Defender, and 15 security fixes for Chrome including two rated critical.
Microsoft Patches Record 570 Windows Vulnerabilities in July Update, Including Three Actively Exploited Zero-Days
Microsoft released its largest Patch Tuesday update to date, addressing 570 vulnerabilities across Windows and related products. Among them are three zero-day flaws, two of which have already been exploited in real-world attacks. Fifty-nine issues were rated critical, with 48 enabling remote code execution. The company credited its use of AI for discovering more vulnerabilities in the Windows codebase. The update covers a wide range of components including .NET, Active Directory services, Microsoft Office, Azure services, and Microsoft Defender. Administrators are urged to apply the patches promptly to mitigate risks from privilege escalation, remote code execution, and information disclosure flaws.