From 0b6e503627c8edc22a8c4ef7eebd5337cf88d8e5 Mon Sep 17 00:00:00 2001
From: Thomas Stromberg <t+github@chainguard.dev>
Date: Fri, 10 Feb 2023 10:22:13 -0500
Subject: [PATCH] New check: Launch Constraint Violation (macOS)

---
 .../execution/launch-constraint-violation.sql | 69 +++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 detection/execution/launch-constraint-violation.sql

diff --git a/detection/execution/launch-constraint-violation.sql b/detection/execution/launch-constraint-violation.sql
new file mode 100644
index 0000000..ea08cb1
--- /dev/null
+++ b/detection/execution/launch-constraint-violation.sql
@@ -0,0 +1,69 @@
+-- Catch programs that failed to run due to signing problems
+--
+-- references:
+--   * https://attack.mitre.org/techniques/T1204/
+--
+-- false positives:
+--   * software installers and updaters
+--   * developers running programs out of /tmp
+--
+-- interval: 600
+-- platform: darwin
+-- tags: filesystem events
+SELECT
+  -- Child
+  pe.path AS p0_path,
+  s.authority AS p0_sauth,
+  s.identifier AS p0_sid,
+  REGEX_MATCH (pe.path, '.*/(.*)', 1) AS p0_name,
+  TRIM(pe.cmdline) AS p0_cmd,
+  p.cwd AS p0_cwd,
+  pe.pid AS p0_pid,
+  pe.euid AS p0_euid,
+  -- Parent
+  pe.parent AS p1_pid,
+  TRIM(COALESCE(p1.cmdline, pe1.cmdline)) AS p1_cmd,
+  COALESCE(p1.path, pe1.path) AS p1_path,
+  p1.cwd AS p1_cwd,
+  COALESCE(p_hash1.sha256, pe_hash1.sha256) AS p1_hash,
+  REGEX_MATCH (COALESCE(p1.path, pe1.path), '.*/(.*)', 1) AS p1_name,
+  -- Grandparent
+  COALESCE(p1.parent, pe1.parent) AS p2_pid,
+  TRIM(
+    COALESCE(p1_p2.cmdline, pe1_p2.cmdline, pe1_pe2.cmdline)
+  ) AS p2_cmd,
+  p1_p2.cwd AS p2_cwd,
+  COALESCE(p1_p2.path, pe1_p2.path, pe1_pe2.path) AS p2_path,
+  COALESCE(
+    p1_p2_hash.path,
+    pe1_p2_hash.path,
+    pe1_pe2_hash.path
+  ) AS p2_hash,
+  REGEX_MATCH (
+    COALESCE(p1_p2.path, pe1_p2.path, pe1_pe2.path),
+    '.*/(.*)',
+    1
+  ) AS p2_name
+FROM
+  process_events pe
+  LEFT JOIN signature s ON pe.path = s.path
+  LEFT JOIN processes p ON pe.pid = p.pid
+  -- Parents (via two paths)
+  LEFT JOIN processes p1 ON pe.parent = p1.pid
+  LEFT JOIN hash p_hash1 ON p1.path = p_hash1.path
+  LEFT JOIN process_events pe1 ON pe.parent = pe1.pid
+  AND pe1.cmdline != ''
+  LEFT JOIN hash pe_hash1 ON pe1.path = pe_hash1.path
+  -- Grandparents (via 3 paths)
+  LEFT JOIN processes p1_p2 ON p1.parent = p1_p2.pid -- Current grandparent via parent processes
+  LEFT JOIN processes pe1_p2 ON pe1.parent = pe1_p2.pid -- Current grandparent via parent events
+  LEFT JOIN process_events pe1_pe2 ON pe1.parent = pe1_p2.pid
+  AND pe1_pe2.cmdline != '' -- Past grandparent via parent events
+  LEFT JOIN hash p1_p2_hash ON p1_p2.path = p1_p2_hash.path
+  LEFT JOIN hash pe1_p2_hash ON pe1_p2.path = pe1_p2_hash.path
+  LEFT JOIN hash pe1_pe2_hash ON pe1_pe2.path = pe1_pe2_hash.path
+WHERE pe.time > (strftime('%s', 'now') -600)
+  AND pe.status = 1
+  AND pe.cmdline != ''
+  AND pe.cmdline IS NOT NULL
+GROUP BY pe.euid, pe.path, pe.cmdline
\ No newline at end of file