From 9807bebd8e2f89413146c60a591be9a103fe398b Mon Sep 17 00:00:00 2001
From: Ruben Groenewoud <78494512+Aegrah@users.noreply.github.com>
Date: Mon, 23 Oct 2023 17:18:48 +0200
Subject: [PATCH] [New BBR] Unix Socket Communication (#3072)

* [New Rule] Unix Socket Communication

* Update rules_building_block/execution_unix_socket_communication.toml

Co-authored-by: Isai <59296946+imays11@users.noreply.github.com>

* Update rules_building_block/execution_unix_socket_communication.toml

---------

Co-authored-by: Isai <59296946+imays11@users.noreply.github.com>
---
 .../execution_unix_socket_communication.toml  | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 rules_building_block/execution_unix_socket_communication.toml

diff --git a/rules_building_block/execution_unix_socket_communication.toml b/rules_building_block/execution_unix_socket_communication.toml
new file mode 100644
index 000000000..6e33fe6a8
--- /dev/null
+++ b/rules_building_block/execution_unix_socket_communication.toml
@@ -0,0 +1,50 @@
+[metadata]
+creation_date = "2023/09/04"
+integration = ["endpoint"]
+maturity = "production"
+min_stack_comments = "New fields added: required_fields, related_integrations, setup"
+min_stack_version = "8.3.0"
+updated_date = "2023/09/04"
+bypass_bbr_timing = true
+
+[rule]
+author = ["Elastic"]
+description = """
+This rule monitors for inter-process communication via Unix sockets. Adversaries may attempt to communicate with local 
+Unix sockets to enumerate application details, find vulnerabilities/configuration mistakes and potentially escalate 
+privileges or set up malicious communication channels via Unix sockets for inter-process communication to attempt to 
+evade detection. 
+"""
+from = "now-9m"
+index = ["logs-endpoint.events.*"]
+language = "eql"
+license = "Elastic License v2"
+name = "Unix Socket Connection"
+risk_score = 21
+rule_id = "41284ba3-ed1a-4598-bfba-a97f75d9aba2"
+severity = "low"
+tags = ["Domain: Endpoint", "OS: Linux", "Use Case: Threat Detection", "Tactic: Execution", "Data Source: Elastic Defend", "Rule Type: BBR"]
+timestamp_override = "event.ingested"
+building_block_type = "default"
+type = "eql"
+query = '''
+process where host.os.type == "linux" and event.action == "exec" and event.type == "start" and (
+  (process.name in ("nc", "ncat", "netcat", "nc.openbsd") and 
+   process.args == "-U" and process.args : ("/usr/local/*", "/run/*", "/var/run/*")) or
+  (process.name == "socat" and 
+   process.args == "-" and process.args : ("UNIX-CLIENT:/usr/local/*", "UNIX-CLIENT:/run/*", "UNIX-CLIENT:/var/run/*"))
+)
+'''
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+
+[[rule.threat.technique]]
+id = "T1559"
+name = "Inter-Process Communication"
+reference = "https://attack.mitre.org/techniques/T1559/"
+
+[rule.threat.tactic]
+id = "TA0002"
+name = "Execution"
+reference = "https://attack.mitre.org/tactics/TA0002/"