When Windows Defender's Defense Becomes the Attack: A Privilege Escalation Flaw

A critical vulnerability in Windows Defender's file handling logic transforms the system's primary defense mechanism into an attack vector. When the antivirus encounters cloud-tagged malicious files, it inadvertently rewrites them to their original location instead of removing them—a behavior attackers can exploit to overwrite system files and gain administrative privileges. This flaw raises fundamental questions about the reliability of complex antimalware heuristics and their unintended security consequences.