sigma-rules/rules/ml/execution_ml_windows_anomalous_script.toml

[metadata]
creation_date = "2020/03/25"
maturity = "production"
updated_date = "2023/03/06"
min_stack_comments = "New fields added: required_fields, related_integrations, setup"
min_stack_version = "8.3.0"

[rule]
anomaly_threshold = 50
author = ["Elastic"]
description = """
A machine learning job detected a PowerShell script with unusual data characteristics, such as obfuscation, that may be
a characteristic of malicious PowerShell script text blocks.
"""
false_positives = [
    """
    Certain kinds of security testing may trigger this alert. PowerShell scripts that use high levels of obfuscation or
    have unusual script block payloads may trigger this alert.
    """,
]
from = "now-45m"
interval = "15m"
license = "Elastic License v2"
machine_learning_job_id = ["v3_windows_anomalous_script"]
name = "Suspicious Powershell Script"
references = [
    "https://www.elastic.co/guide/en/security/current/prebuilt-ml-jobs.html",
    "https://www.elastic.co/security-labs/detecting-living-off-the-land-attacks-with-new-elastic-integration"]
risk_score = 21
rule_id = "1781d055-5c66-4adf-9d60-fc0fa58337b6"
severity = "low"
tags = ["Elastic", "Host", "Windows", "Threat Detection", "ML", "Machine Learning", "Execution"]
type = "machine_learning"

[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1059"
name = "Command and Scripting Interpreter"
reference = "https://attack.mitre.org/techniques/T1059/"


    [[rule.threat.technique.subtechnique]]
    id = "T1059.001"
    name = "PowerShell"
    reference = "https://attack.mitre.org/techniques/T1059/001/"


[rule.threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"