Execution via local SxS Shared Module
editExecution via local SxS Shared Module
editIdentifies the creation, change, or deletion of a DLL module within a Windows SxS local folder. Adversaries may abuse shared modules to execute malicious payloads by instructing the Windows module loader to load DLLs from arbitrary local paths.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.file-*
- logs-windows.sysmon_operational-*
- endgame-*
Severity: medium
Risk score: 47
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: Execution
- Data Source: Elastic Endgame
- Data Source: Elastic Defend
- Data Source: Sysmon
Version: 108
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guide
editTriage and analysis
The SxS DotLocal folder is a legitimate feature that can be abused to hijack standard modules loading order by forcing an executable on the same application.exe.local folder to load a malicious DLL module from the same directory.
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
editfile where host.os.type == "windows" and file.extension : "dll" and file.path : "C:\\*\\*.exe.local\\*.dll"
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
-
Technique:
- Name: Shared Modules
- ID: T1129
- Reference URL: https://attack.mitre.org/techniques/T1129/