EDR evasion

A new method allows attackers to extract Windows secrets and credentials without being detected by most Endpoint Detection and Response (EDR) solutions. This technique enables individuals with access to a Windows machine to gather credentials for lateral movement within a network. The Local Security Authority (LSA) manages sensitive information through two in-memory databases: the SAM database, which stores user credentials, and the Security database, which holds LSA secrets. Access to these databases requires interaction with the SAM and SECURITY registry hives, protected by Discretionary Access Control Lists (DACLs) that limit access to SYSTEM privileges. Attackers typically face detection when accessing the lsass.exe process memory, as EDR solutions monitor high-risk activities. Researcher Sud0Ru has introduced a method that bypasses these defenses by using the undocumented API NtOpenKeyEx with the REGOPTIONBACKUPRESTORE flag, allowing attackers to read the SAM and SECURITY hives without SYSTEM-level privileges. To avoid detection, attackers use the RegQueryMultipleValuesW API, which is less monitored by EDRs, to extract encrypted secrets from the hives. This approach allows the operation to occur entirely in memory, leaving no on-disk artifacts and evading typical security alerts.