Windows Defender

Hacker or Engineer? Reconstructing Attack Chains in Industrial OT Networks

Positive Technologies expert Anton Kutepov presents a detailed educational scenario from the Standoff online polygon to demonstrate how security teams can trace an attack from initial perimeter compromise to unauthorized writes on a PLC. The case begins with an unexpected SCADA server command to a hydrocracking unit controller outside the maintenance window. By correlating network traffic, endpoint telemetry, authentication logs, and asset context, analysts reconstruct the full path: exploitation of a vulnerable DMZ system, lateral movement via Kerberoasting and Active Directory certificate abuse, RDP access to an engineering workstation, and finally weakening of Windows Defender on the SCADA server before issuing the control command. The analysis shows that a single permitted industrial protocol operation becomes suspicious only when placed in the context of prior defensive control changes and anomalous access routes. The article stresses that protecting OT environments requires continuous asset inventory, unified telemetry from traffic and endpoints, and pre-approved response playbooks that avoid disrupting the physical process.

Microsoft Releases Fix for Windows Defender Crashes During Quick and Full Scans

Microsoft has issued a security intelligence update to resolve a crash in Windows Defender that occurred during quick or full system scans on affected Windows 10 and Windows 11 devices. The bug, introduced after a recent set of patches, caused the antivirus service to terminate unexpectedly with the message "Threat service has stopped. Restart it" and access violation error 0xc0000005. Some users misinterpreted the repeated failures as malware infection or severe system damage, leading them to reinstall Windows entirely. Administrators were able to reproduce the issue consistently across multiple machines simply by initiating a quick scan, confirming the root cause lay in Defender itself rather than individual endpoints. The fix is included in security intelligence version 1.457.236.0 and all subsequent releases, with Microsoft advising users to ensure automatic updates are applied via Windows Update or manually through the Windows Security interface.

Windows Defender Patch for RoguePlanet Zero-Day Vulnerability May Exhaust Disk Space on Windows Systems

Microsoft released a security update addressing the RoguePlanet zero-day vulnerability (CVE-2026-50656) in the Microsoft Malware Protection Engine used by Windows Defender. The flaw, disclosed earlier by researcher NightmareEclipse, allowed remote attackers to gain administrative control over Windows 10 and Windows 11 even when real-time protection was disabled. While the patch was intended to resolve the issue and deploy automatically, the researcher now claims it introduces a new problem involving excessive disk writes. Specifically, the update may cause Defender to cache extremely large Zone.Identifier alternate data streams without size limits, potentially filling the entire drive. The attack vector involves a malicious SMB server that serves oversized metadata streams while maintaining the connection. Microsoft has not yet confirmed the reported behavior, and tensions between the company and the researcher continue over disclosure practices and bug bounty rewards.