new detector: unexpected fetcher parents

detection/execution/unexpected-fetcher-parent-events.sql

@@ -0,0 +1,84 @@
+-- Suspicious parenting of fetch tools (event-based)
+--
+-- refs:
+--   * https://attack.mitre.org/techniques/T1105/ (Ingress Tool Transfer)
+--
+-- tags: transient process state often
+-- platform: posix
+-- interval: 900
+SELECT pe.path AS child_path,
+    REGEX_MATCH (pe.path, '.*/(.*)', 1) AS child_name,
+    TRIM(pe.cmdline) AS child_cmd,
+    pe.pid AS child_pid,
+    p.cgroup_path AS child_cgroup,
+    p.parent AS parent_pid,
+    TRIM(IIF(pp.cmdline != NULL, pp.cmdline, ppe.cmdline)) AS parent_cmd,
+    TRIM(IIF(pp.path != NULL, pp.path, ppe.path)) AS parent_path,
+    REGEX_MATCH (
+        IIF(pp.path != NULL, pp.path, ppe.path),
+        '.*/(.*)',
+        1
+    ) AS parent_name,
+    TRIM(IIF(gp.cmdline != NULL, gp.cmdline, gpe.cmdline)) AS gparent_cmd,
+    TRIM(IIF(gp.path != NULL, gp.path, gpe.path)) AS gparent_path,
+    REGEX_MATCH (
+        IIF(gp.path != NULL, gp.path, gpe.path),
+        '.*/(.*)',
+        1
+    ) AS gparent_name,
+    IIF(pp.parent != NULL, pp.parent, ppe.parent) AS gparent_pid,
+    CONCAT(
+        REGEX_MATCH (pe.path, '.*/(.*)', 1),
+        ',',
+        MIN(pe.euid, 500),
+        ',',
+        REGEX_MATCH (
+            IIF(pp.path != NULL, pp.path, ppe.path),
+            '.*/(.*)',
+            1
+        ),
+        ',',
+        REGEX_MATCH (
+            IIF(gp.path != NULL, gp.path, gpe.path),
+            '.*/(.*)',
+            1
+        )
+    ) AS exception_key
+FROM process_events pe
+    LEFT JOIN processes p ON pe.pid = p.pid
+    LEFT JOIN processes pp ON pe.parent = pp.pid
+    LEFT JOIN process_events ppe ON pe.parent = ppe.pid
+    LEFT JOIN processes gp ON gp.pid = pp.parent
+    LEFT JOIN process_events gpe ON ppe.parent = gpe.pid
+WHERE child_name IN ('curl', 'wget', 'ftp', 'tftp')
+    AND pe.time > (strftime('%s', 'now') -900) -- Ignore partial table joins
+    AND NOT (
+        pe.euid > 500
+        AND parent_name IN ('sh', 'fish', 'zsh', 'bash', 'dash')
+        AND gparent_name IN (
+            'alacritty',
+            'gnome-terminal-',
+            'roxterm',
+            'tmux',
+            'tmux:server',
+            'wezterm-gui',
+            'kitty',
+            'zsh'
+        )
+    )
+    AND NOT parent_name IN ('yay')
+    AND NOT exception_key IN (
+      'curl,500,fish,gnome-terminal-',
+      'curl,500,bash,zsh'
+    )
+    AND NOT (
+        pe.euid > 500 AND
+        parent_name = 'env' AND
+        parent_cmd LIKE '/usr/bin/env -i % HOMEBREW_BREW_FILE=%'
+    )
+    AND NOT (
+        pe.euid > 500 AND
+        parent_name = 'ruby' AND
+        parent_cmd LIKE '%/opt/homebrew/Library/Homebrew/brew.rb%'
+    )
+GROUP BY pe.pid

detection/execution/unexpected-fetcher-parents.sql

@@ -0,0 +1,67 @@
+-- Suspicious parenting of fetch tools (state-based)
+--
+-- refs:
+--   * https://attack.mitre.org/techniques/T1105/ (Ingress Tool Transfer)
+--
+-- tags: transient process state often
+-- platform: posix
+SELECT p.pid,
+  p.path,
+  p.name AS child_name,
+  p.cmdline,
+  p.cwd,
+  p.euid,
+  p.parent,
+  p.cgroup_path,
+  pp.path AS parent_path,
+  pp.name AS parent_name,
+  pp.cmdline AS parent_cmd,
+  pp.euid AS parent_euid,
+  gp.name AS gparent_name,
+  gp.cmdline AS gparent_cmd,
+  pp.pid AS gparent_pid,
+  hash.sha256 AS parent_sha256,
+  CONCAT(
+    p.name,
+    ',',
+    MIN(p.euid, 500),
+    ',',
+    pp.name,
+    ',',
+    gp.name
+  ) AS exception_key
+FROM processes p
+  LEFT JOIN processes pp ON p.parent = pp.pid
+  LEFT JOIN processes gp ON pp.parent = gp.pid
+  LEFT JOIN hash ON pp.path = hash.path
+WHERE child_name IN ('curl', 'wget', 'ftp', 'tftp') -- And not a regular local user
+  AND NOT (
+    p.euid > 500
+    AND parent_name IN ('sh', 'fish', 'zsh', 'bash', 'dash')
+    AND gparent_name IN (
+      'alacritty',
+      'gnome-terminal-',
+      'roxterm',
+      'tmux',
+      'tmux:server',
+      'wezterm-gui',
+      'kitty',
+      'zsh'
+    )
+  )
+  AND NOT parent_name IN ('yay')
+  AND NOT exception_key IN (
+    'curl,500,fish,gnome-terminal-',
+    'curl,500,bash,zsh'
+  )
+  AND NOT (
+    p.euid > 500
+    AND parent_name = 'env'
+    AND parent_cmd LIKE '/usr/bin/env -i % HOMEBREW_BREW_FILE=%'
+  )
+  AND NOT (
+    p.euid > 500
+    AND parent_name = 'ruby'
+    AND parent_cmd LIKE '%/opt/homebrew/Library/Homebrew/brew.rb%'
+  )
+GROUP BY p.pid