Boot or Logon Autostart Execution: Authentication Package

Adversaries may abuse authentication packages to execute DLLs when the system boots. Windows authentication package DLLs are loaded by the Local Security Authority (LSA) process at system start. They provide support for multiple logon processes and multiple security protocols to the operating system. [1]

Adversaries can use the autostart mechanism provided by LSA authentication packages for persistence by placing a reference to a binary in the Windows Registry location HKLM\SYSTEM\CurrentControlSet\Control\Lsa\ with the key value of "Authentication Packages"=<target binary>. The binary will then be executed by the system when the authentication packages are loaded.

ID: T1547.002
Sub-technique of:  T1547
Tactics: Persistence, Privilege Escalation
Platforms: Windows
Permissions Required: Administrator
Data Sources: DLL monitoring, Loaded DLLs, Windows Registry
Version: 1.0
Created: 24 January 2020
Last Modified: 25 March 2020

Procedure Examples

Name Description
Flame

Flame can use Windows Authentication Packages for persistence.[4]

Mitigations

Mitigation Description
Privileged Process Integrity

Windows 8.1, Windows Server 2012 R2, and later versions, may make LSA run as a Protected Process Light (PPL) by setting the Registry key HKLM\SYSTEM\CurrentControlSet\Control\Lsa\RunAsPPL, which requires all DLLs loaded by LSA to be signed by Microsoft. [2] [3]

Detection

Monitor the Registry for changes to the LSA Registry keys. Monitor the LSA process for DLL loads. Windows 8.1 and Windows Server 2012 R2 may generate events when unsigned DLLs try to load into the LSA by setting the Registry key HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\LSASS.exe with AuditLevel = 8. [2] [3]

References