Potential DLL Side-Loading via Microsoft Antimalware Service Executable
editPotential DLL Side-Loading via Microsoft Antimalware Service Executable
editIdentifies a Windows trusted program that is known to be vulnerable to DLL Search Order Hijacking starting after being renamed or from a non-standard path. This is uncommon behavior and may indicate an attempt to evade defenses via side-loading a malicious DLL within the memory space of one of those processes.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
- logs-windows.sysmon_operational-*
- endgame-*
Severity: high
Risk score: 73
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Defense Evasion
- Data Source: Elastic Endgame
- Tactic: Execution
- Data Source: Elastic Defend
- Data Source: Sysmon
Version: 109
Rule authors:
- Elastic
- Dennis Perto
Rule license: Elastic License v2
Setup
editSetup
If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2,
events will not define event.ingested
and default fallback for EQL rules was not added until version 8.2.
Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate
event.ingested
to @timestamp.
For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html
Rule query
editprocess where host.os.type == "windows" and event.type == "start" and ( (process.pe.original_file_name == "MsMpEng.exe" and not process.name : "MsMpEng.exe") or (process.name : "MsMpEng.exe" and not process.executable : ("?:\\ProgramData\\Microsoft\\Windows Defender\\*.exe", "?:\\Program Files\\Windows Defender\\*.exe", "?:\\Program Files (x86)\\Windows Defender\\*.exe", "?:\\Program Files\\Microsoft Security Client\\*.exe", "?:\\Program Files (x86)\\Microsoft Security Client\\*.exe")) )
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Hijack Execution Flow
- ID: T1574
- Reference URL: https://attack.mitre.org/techniques/T1574/
-
Sub-technique:
- Name: DLL Side-Loading
- ID: T1574.002
- Reference URL: https://attack.mitre.org/techniques/T1574/002/