Gabriel Landau's blog post discusses a Windows exploit that allows attackers to perform highly privileged actions typically requiring a kernel driver by exploiting a vulnerability in the DefineDosDevice API to tamper with the KnownDlls cache. This exploit, affecting Windows 10 version 21H1, enables attackers to inject a DLL into a Protected Process Light (PPL) process, thereby performing actions with WinTcb privileges, such as dumping enterprise credentials and disabling security products. The blog highlights the release of PPLDump, an open-source tool showcasing this exploit, and its subsequent adaptation into Sealighter-TI, which accesses restricted Threat-Intelligence feeds. To address the vulnerability, the blog introduces PPLGuard, a tool that hardens the KnownDlls object directory by applying a dynamic access control list (DACL) to block the exploit. The post emphasizes the potential for offensive tools to exploit this vulnerability and hints at a future discussion on using Elastic Security to detect such attacks.