As antimalware (AM) software has become better and better at detecting runtime malware, attackers are also becoming better at creating rootkits that can hide from detection. Detecting malware that starts early in the boot cycle is a challenge that most AM vendors address diligently. Typically, they create system hacks that are not supported by the host operating system and can actually result in placing the computer in an unstable state. Up to this point, Windows has not provided a good way for AM to detect and resolve these early boot threats.
Windows 8 and Windows 10 include a feature called Secure Boot, which protects the Windows boot configuration and components, and loads an Early Launch Antimalware (ELAM) driver. This driver starts before other boot-start drivers and enables the evaluation of those drivers and helps the Windows kernel decide whether they should be initialized.
The Boot-Start Driver Initialization Policy setting allows you to specify which boot-start drivers are initialized based on a classification determined by an Early Launch Antimalware boot-start driver. The Early Launch Antimalware boot-start driver can return the following classifications for each boot-start driver:
• Good -The driver has been signed and has not been tampered with.
• Bad – The driver has been identified as malware. It is recommended that you do not allow known bad drivers to be initialized.
• Bad, but required for boot – The driver has been identified as malware, but the computer cannot successfully boot without loading this driver.
• Unknown – This driver has not been attested to by your malware detection application and has not been classified by the Early Launch Antimalware boot-start driver.
If you enable this policy setting you will be able to choose which boot-start drivers to initialize the next time the computer is started.
If you disable or do not configure this policy setting, the boot start drivers determined to be Good, Unknown or Bad but Boot Critical are initialized and the initialization of drivers determined to be Bad is skipped.
If your malware detection application does not include an Early Launch Antimalware boot-start driver or if your Early Launch Antimalware boot-start driver has been disabled, this setting has no effect and all boot-start drivers are initialized.
This tutorial will show you how to configure the Early Launch Antimalware Boot-Start Driver Initialization Policy in Windows 8 and Windows 10.