Researchers found, and Microsoft has patched, a vulnerability in Windows Defender that has been around for twelve years. There is no evidence that anyone has used the vulnerability during that time.
The flaw, discovered by researchers at the security firm SentinelOne, showed up in a driver that Windows Defender — renamed Microsoft Defender last year — uses to delete the invasive files and infrastructure that malware can create. When the driver removes a malicious file, it replaces it with a new, benign one as a sort of placeholder during remediation. But the researchers discovered that the system doesn’t specifically verify that new file. As a result, an attacker could insert strategic system links that direct the driver to overwrite the wrong file or even run malicious code.
It isn’t unusual that vulnerabilities lie around for this long. They can’t be fixed until someone finds them, and people aren’t always looking.
Read more: schneier.com