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Disabling Lsa Protection via Registry Modification

LSA protecton is provided to prevent nonprotected processes from reading memory and injecting code. This feature provides added security for the credentials that LSA stores and manages. Adversaries may modify the RunAsPPL registry and wait or initiate a system restart to enable Lsass credentials access.

Rule type: eql
Rule indices:

  • winlogbeat-*
  • logs-endpoint.events.registry-*
  • logs-windows.sysmon_operational-*
  • endgame-*
  • logs-m365_defender.event-*
  • logs-sentinel_one_cloud_funnel.*

Rule Severity: high
Risk Score: 73
Runs every:
Searches indices from: now-9m
Maximum alerts per execution: ?
References:

Tags:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Tactic: Defense Evasion
  • Resources: Investigation Guide
  • Data Source: Elastic Endgame
  • Data Source: Elastic Defend
  • Data Source: Sysmon
  • Data Source: Microsoft Defender for Endpoint
  • Data Source: SentinelOne

Version: ?
Rule authors:

  • Elastic

Rule license: Elastic License v2

For more information about the Lsa Protection and how it works, check the official Microsoft docs page.

Attackers may disable Lsa protection to access Lsass memory for credentals. This rule identifies RunAsPPL registry value modifications.

  • Verify the context of the change and if it's related to a planned system administration activity.
  • Investigate the process execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.
  • Investigate other alerts associated with the user/host during the past 48 hours.
  • Inspect the host for suspicious or abnormal behaviors in the alert timeframe.
  • Investigate abnormal behaviors observed by the subject process such as network connections, registry or file modifications, and any spawned child processes.
  • Approved changes to relax the Lsa protection for compatibility with third party solutions such as authentication plugins or alike.
  • Initiate the incident response process based on the outcome of the triage.
  • Isolate the involved host to prevent further post-compromise behavior.
  • If the triage identified malware, search the environment for additional compromised hosts.
    • Implement temporary network rules, procedures, and segmentation to contain the malware.
    • Stop suspicious processes.
    • Immediately block the identified indicators of compromise (IoCs).
    • Inspect the affected systems for additional malware backdoors like reverse shells, reverse proxies, or droppers that attackers could use to reinfect the system.
  • Remove and block malicious artifacts identified during triage.
  • Restore UAC settings to the desired state.
  • Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.
  • Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.
  • Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.
  • Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).
registry where host.os.type == "windows" and event.type == "change" and
  registry.path : ("HKLM\\SYSTEM\\ControlSet*\\Control\\Lsa\\RunAsPPL", "\\REGISTRY\\MACHINE\\SYSTEM\\ControlSet*\\Control\\Lsa\\RunAsPPL") and
  not registry.data.strings : ("1", "0x00000001", "2", "0x00000002")

Framework: MITRE ATT&CK