Unusual Executable Name Linux

Processes with executable names that feel weird

Description

ODK (osquery-defense-kit) is unique in that the queries are designed to be used as part of a production detection & response pipeline. The detection queries are formulated to return zero rows during normal expected behavior, so that they may be configured to generate alerts when rows are returned.

Query

-- Processes with executable names that feel weird
--
-- references:
--   * https://www.zscaler.com/blogs/security-research/peek-apt36-s-updated-arsenal
--
-- tags: persistent process
SELECT
  COALESCE(REGEX_MATCH (p0.path, '.*/(.*)', 1), p0.path) AS pname,
  COALESCE(
    REGEX_MATCH (p0.path, '.*/.*\\.([a-z]{2,4})$', 1),
    ""
  ) AS pext,
  -- Child
  p0.pid AS p0_pid,
  p0.path AS p0_path,
  p0.name AS p0_name,
  p0.cmdline AS p0_cmd,
  p0.cwd AS p0_cwd,
  p0.euid AS p0_euid,
  p0_hash.sha256 AS p0_sha256,
  -- Parent
  p0.parent AS p1_pid,
  p1.path AS p1_path,
  p1.name AS p1_name,
  p1.euid AS p1_euid,
  p1.cmdline AS p1_cmd,
  p1_hash.sha256 AS p1_sha256,
  -- Grandparent
  p1.parent AS p2_pid,
  p2.name AS p2_name,
  p2.path AS p2_path,
  p2.cmdline AS p2_cmd,
  p2_hash.sha256 AS p2_sha256
FROM
  processes p0
  LEFT JOIN hash p0_hash ON p0.path = p0_hash.path
  LEFT JOIN processes p1 ON p0.parent = p1.pid
  LEFT JOIN hash p1_hash ON p1.path = p1_hash.path
  LEFT JOIN processes p2 ON p1.parent = p2.pid
  LEFT JOIN hash p2_hash ON p2.path = p2_hash.path
WHERE
  (
    pname LIKE "%kthread%"
    OR pname LIKE '%xprotect%'
    OR pname LIKE "%-help"
    OR pname LIKE "%acpi%"
    OR pname LIKE "%crypt%"
    OR pname LIKE "%flush%"
    OR pname LIKE "%initd%"
    OR pname LIKE "%irq%"
    OR pname LIKE "%kaudit%"
    OR pname LIKE "%kdev%"
    OR pname LIKE "%kdmp%"
    OR pname LIKE "%ksoft%"
    OR pname LIKE "%kswap%"
    OR pname LIKE "%kworker%"
    OR pname LIKE "%launchd%"
    OR pname LIKE "%nvme%"
    OR pname LIKE "%tasks%"
    OR pname LIKE "%thread%"
    OR pname LIKE "%user_dir%"
    OR pname LIKE "%xdg%"
    OR pname LIKE "%zswap%"
    OR pname LIKE "cpu%"
    OR pname LIKE "events%"
    OR pname LIKE "idle_%"
    OR pname LIKE "mm-%"
    OR pname LIKE "nm_%"
    OR pname LIKE "rcu%"
    OR REGEX_MATCH (pname, '([a-z]{16,})', 1) != ""
    OR REGEX_MATCH (pname, '([a-zA-Z0-9]{32,})', 1) != ""
    OR REGEX_MATCH (pname, '(\\w{40,})', 1) != ""
    OR REGEX_MATCH (
      pname,
      '([a-z]+[A-Z]+[a-z]+[A-Z]+[a-z]+[A-Z]+[a-z]+[A-Z]+[a-z]+[A-Z]+[a-z]+[A-Z]+)',
      1
    ) != ""
    OR REGEX_MATCH (pname, "([a-z].*[A-Z].*\\d+.*[a-z].*\\d+)", 1) != ""
    OR REGEX_MATCH (pname, "(\\d.*[a-z].*\\d.*[a-z].*\\d+)", 1) != ""
    OR REGEX_MATCH (pname, "(\\d{5,})", 1) != ""
    OR REGEX_MATCH (pname, "^(\\d\\d)", 1) != ""
    OR REGEX_MATCH (pname, "^(\\W)", 1) != ""
    OR (
      REGEX_MATCH (pname, "(\\W)$", 1) != ""
      AND pname NOT LIKE "%)"
    )
    AND pext NOT IN ("", "gui", "cli", "us", "node", "com", "test")
  )
  AND NOT pname LIKE '.%-wrapped'
  AND NOT pname LIKE '__debug_bin%'
  AND NOT pname LIKE '__Test%.test'
  AND pname NOT IN (
    "acpid",
    "akonadi_followupreminder_agent",
    "gmenudbusmenuproxy",
    "irqbalance",
    "kactivitymanagerd",
    "nm-applet",
    "nm-dispatcher",
    "xdg-dbus-proxy",
    "xdg-desktop-portal-gnome",
    "xdg-desktop-portal-gtk",
    "xdg-desktop-portal-kde",
    "xdg-desktop-portal-regolith",
    "xdg-desktop-portal-xapp",
    "xdg-desktop-portal",
    "xdg-document-portal",
    "xdg-permission-store",
    "xwaylandvideobridge"
  )

tags: SStagSS

Reference

https://github.com/chainguard-dev/osquery-defense-kit