SignDrop, disclosed Tuesday, gives ordinary Windows users System rights.

Nightmare Eclipse says it can switch off any antivirus.

An attacker makes Defender open a crafted log container, and the logging service creates a missing file with System privileges.

Researcher Will Dormann reproduced it, but only 1 of his machines met the requirements.

Microsoft representatives did not answer a request for comment on a fix.

How each outlet framed it
Ars Technica leans critical
frames the exploit as Windows Defender turned against itself, tracing the CLFS flaw through the signature-update function

Sources: Ars Technica