Researcher bypasses Microsoft Defender security patch, seizing control

Just weeks after Microsoft patched a critical hole in Microsoft Defender, a cybersecurity researcher has posted an apparent bypass that provides system-level control to attackers once they gain any level of access. The researcher, who goes by the name Nightmare Eclipse, has been engaged in a long-running battle with Microsoft Security.

Nightmare Eclipse has not provided the further details we requested, however Microsoft sent a brief statement, saying, “Microsoft is aware of the reported vulnerability and is actively investigating the validity and potential applicability of these claims,” and reiterating its commitment to investigating issues and supporting coordinated disclosure.

But the proof of concept (PoC) security bypass, ShieldBreak, described by Nightmare Eclipse in a series of public posts, potentially threatens to be more damaging than earlier bypass.