Boot or Logon Initialization Scripts: Network Logon Script

Adversaries may use network logon scripts automatically executed at logon initialization to establish persistence. Network logon scripts can be assigned using Active Directory or Group Policy Objects.[1] These logon scripts run with the privileges of the user they are assigned to. Depending on the systems within the network, initializing one of these scripts could apply to more than one or potentially all systems.

Adversaries may use these scripts to maintain persistence on a network. Depending on the access configuration of the logon scripts, either local credentials or an administrator account may be necessary.

ID: T1037.003
Sub-technique of:  T1037
Platforms: Windows
Version: 1.0
Created: 10 January 2020
Last Modified: 24 March 2020

Mitigations

ID Mitigation Description
M1022 Restrict File and Directory Permissions

Restrict write access to logon scripts to specific administrators.

Detection

ID Data Source Data Component
DS0026 Active Directory Active Directory Object Modification
DS0017 Command Command Execution
DS0022 File File Creation
File Modification
DS0009 Process Process Creation

Monitor logon scripts for unusual access by abnormal users or at abnormal times. Look for files added or modified by unusual accounts outside of normal administration duties. Monitor running process for actions that could be indicative of abnormal programs or executables running upon logon.

References