osquery-defense-kit/detection/evasion/unexpected-var-executables-linux.sql

-- Find unexpected executables in /var
--
-- false positives:
--   * none known
--
-- tags: persistent
-- platform: linux
SELECT file.path,
  file.directory,
  uid,
  gid,
  mode,
  file.mtime,
  file.size,
  hash.sha256,
  magic.data
FROM file
  LEFT JOIN hash on file.path = hash.path
  LEFT JOIN magic ON file.path = magic.path
WHERE (
    -- This list is the result of multiple queries combined and can likely be minimized
    file.path LIKE '/var/%%'
    OR file.path LIKE '/var/tmp/%%'
    OR file.path LIKE '/var/tmp/.%/%%'
    OR file.path LIKE '/var/tmp/%/%%'
    OR file.path LIKE '/var/tmp/%/%/.%'
    OR file.path LIKE '/var/tmp/%/.%/%%'
    OR file.path LIKE '/var/spool/%%'
    OR file.path LIKE '/var/spool/.%/%%'
    OR file.path LIKE '/var/spool/%/%%'
    OR file.path LIKE '/var/spool/%/%/.%'
    OR file.path LIKE '/var/spool/%/.%/%%'
  )
  AND file.type = 'regular'
  AND file.path NOT LIKE '%/../%'
  AND file.path NOT LIKE '%/./%'
  AND (
    file.mode LIKE '%7%'
    OR file.mode LIKE '%5%'
    OR file.mode LIKE '%1%'
  )
  AND file.directory NOT IN (
    '/var/lib/colord',
    '/var/ossec/agentless',
    '/var/ossec/bin',
    '/var/ossec/wodles',
    '/var/run/booted-system',
    '/var/run/current-system'
  )
  AND file.size > 10