90 lines
2.9 KiB
TOML
90 lines
2.9 KiB
TOML
[metadata]
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creation_date = "2020/03/25"
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integration = ["endpoint", "windows"]
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maturity = "production"
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min_stack_comments = "Multiple field support in the New Terms rule type was added in Elastic 8.6"
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min_stack_version = "8.6.0"
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updated_date = "2023/10/23"
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[rule]
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author = ["Elastic"]
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description = """
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An instance of MSBuild, the Microsoft Build Engine, started a PowerShell script or the Visual C# Command Line Compiler.
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This technique is sometimes used to deploy a malicious payload using the Build Engine.
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"""
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false_positives = [
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"""
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The Build Engine is commonly used by Windows developers but use by non-engineers is unusual. If a build system
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triggers this rule it can be exempted by process, user or host name.
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""",
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]
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from = "now-9m"
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index = ["winlogbeat-*", "logs-endpoint.events.*", "logs-windows.*"]
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language = "kuery"
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license = "Elastic License v2"
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name = "Microsoft Build Engine Started an Unusual Process"
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references = ["https://blog.talosintelligence.com/2020/02/building-bypass-with-msbuild.html"]
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risk_score = 21
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rule_id = "9d110cb3-5f4b-4c9a-b9f5-53f0a1707ae6"
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setup = """
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If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2,
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events will not define `event.ingested` and default fallback for EQL rules was not added until version 8.2.
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Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate
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`event.ingested` to @timestamp.
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For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html
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"""
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severity = "low"
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tags = ["Domain: Endpoint",
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"OS: Windows",
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"Use Case: Threat Detection",
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"Tactic: Defense Evasion",
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"Tactic: Execution",
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"Data Source: Elastic Defend"
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]
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timestamp_override = "event.ingested"
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type = "new_terms"
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query = '''
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host.os.type:windows and event.category:process and event.type:start and process.parent.name:"MSBuild.exe" and
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process.name.caseless:("csc.exe" or "iexplore.exe" or "powershell.exe")
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'''
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[[rule.threat]]
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framework = "MITRE ATT&CK"
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[[rule.threat.technique]]
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id = "T1027"
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name = "Obfuscated Files or Information"
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reference = "https://attack.mitre.org/techniques/T1027/"
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[[rule.threat.technique.subtechnique]]
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id = "T1027.004"
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name = "Compile After Delivery"
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reference = "https://attack.mitre.org/techniques/T1027/004/"
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[[rule.threat.technique]]
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id = "T1127"
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name = "Trusted Developer Utilities Proxy Execution"
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reference = "https://attack.mitre.org/techniques/T1127/"
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[[rule.threat.technique.subtechnique]]
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id = "T1127.001"
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name = "MSBuild"
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reference = "https://attack.mitre.org/techniques/T1127/001/"
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[rule.threat.tactic]
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id = "TA0005"
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name = "Defense Evasion"
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reference = "https://attack.mitre.org/tactics/TA0005/"
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[rule.new_terms]
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field = "new_terms_fields"
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value = ["host.id", "user.name", "process.parent.command_line"]
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[[rule.new_terms.history_window_start]]
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field = "history_window_start"
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value = "now-14d"
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