[Rule Tuning] Interactive Terminal Spawned via Python (#2781)

* [Rule Tuning] Interactive Terminal Spawned via Python

* Update execution_python_tty_shell.toml

* Update execution_python_tty_shell.toml

* Apply suggestions from code review

Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>

---------

Co-authored-by: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>

rules/linux/execution_python_tty_shell.toml

@@ -2,7 +2,7 @@
 creation_date = "2020/04/15"
 integration = ["endpoint"]
 maturity = "production"
-updated_date = "2023/02/22"
+updated_date = "2023/05/05"
 min_stack_comments = "New fields added: required_fields, related_integrations, setup"
 min_stack_version = "8.3.0"
 
@@ -13,8 +13,8 @@ Identifies when a terminal (tty) is spawned via Python. Attackers may upgrade a
 interactive tty after obtaining initial access to a host.
 """
 from = "now-9m"
-index = ["auditbeat-*", "logs-endpoint.events.*", "endgame-*"]
-language = "kuery"
+index = ["logs-endpoint.events.*"]
+language = "eql"
 license = "Elastic License v2"
 name = "Interactive Terminal Spawned via Python"
 risk_score = 73
@@ -23,15 +23,14 @@ severity = "high"
 tags = ["Elastic", "Host", "Linux", "Threat Detection", "Execution", "Elastic Endgame"]
 timeline_id = "e70679c2-6cde-4510-9764-4823df18f7db"
 timeline_title = "Comprehensive Process Timeline"
-timestamp_override = "event.ingested"
-type = "query"
+type = "eql"
 
 query = '''
-event.category:process and host.os.type:linux and event.type:(start or process_started) and
-  process.name:python* and
-  process.args:("import pty; pty.spawn(\"/bin/sh\")" or
-                "import pty; pty.spawn(\"/bin/dash\")" or
-                "import pty; pty.spawn(\"/bin/bash\")")
+sequence with maxspan=1m
+  [process where host.os.type == "linux" and event.type == "start" and process.name : "python*"] by process.entity_id
+  [process where host.os.type == "linux" and event.type == "start" and 
+   process.executable : "/bin/*sh"
+  ] by process.parent.entity_id
 '''
 
 
@@ -42,6 +41,10 @@ id = "T1059"
 name = "Command and Scripting Interpreter"
 reference = "https://attack.mitre.org/techniques/T1059/"
 
+  [[rule.threat.technique.subtechnique]]
+  id = "T1059.006"
+  name = "Python"
+  reference = "https://attack.mitre.org/techniques/T1059/006/"
 
 [rule.threat.tactic]
 id = "TA0002"