[metadata]
creation_date = "2023/09/20"
integration = ["endpoint"]
maturity = "production"
updated_date = "2023/09/20"
min_stack_comments = "New fields added: required_fields, related_integrations, setup"
min_stack_version = "8.3.0"

[rule]
author = ["Elastic"]
description = """
Identifies when a non-interactive terminal (tty) is being upgraded to a fully interactive shell. Attackers may upgrade 
a simple reverse shell to a fully interactive tty after obtaining initial access to a host, in order to obtain a more 
stable connection.
"""
from = "now-9m"
index = ["logs-endpoint.events.*", "endgame-*"]
language = "eql"
license = "Elastic License v2"
name = "Potential Upgrade of Non-interactive Shell"
risk_score = 47
rule_id = "84d1f8db-207f-45ab-a578-921d91c23eb2"
severity = "medium"
timestamp_override = "event.ingested"
tags = ["Domain: Endpoint",
        "OS: Linux",
        "Use Case: Threat Detection",
        "Tactic: Execution",
        "Data Source: Elastic Endgame",
        "Data Source: Elastic Defend"
        ]
type = "eql"
query = '''
process where host.os.type == "linux" and event.action in ("exec", "exec_event") and event.type == "start" and (
  (process.name == "stty" and process.args == "raw" and process.args == "-echo" and process.args_count >= 3) or
  (process.name == "script" and process.args in ("-qc", "-c") and process.args == "/dev/null" and 
   process.args_count == 4)
)
'''

[[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 = "T1059.004"
name = "Unix Shell"
reference = "https://attack.mitre.org/techniques/T1059/004/"

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