Setxid Env Overflow Attempt
osquery
Find setuid process events with large environment sizes
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
-- Find setuid process events with large environment sizes
--
-- ******************************************************************
-- NOTE: This is a rare case of a non-working query. It does not work
-- in my environment (osquery 5.5.1 running with Kolide) as
-- process_events.env_size is NULL. I believe this to be a bug, but
-- requires more investigation.
-- ******************************************************************
--
-- tags: events process escalation disabled seldom
-- platform: posix
--
-- Uncomment once the underlying problem is addressed:
-- interval: 60
SELECT
file.mode AS p0_binary_mode,
pe.env AS p0_env,
pe.time AS p0_time,
pe.env_size AS p0_env_size,
-- Child
pe.path AS p0_path,
REGEX_MATCH (pe.path, '.*/(.*)', 1) AS p0_name,
TRIM(pe.cmdline) AS p0_cmd,
pe.euid AS p0_euid,
pe.cwd AS p0_cwd,
pe.pid AS p0_pid,
p.cgroup_path AS p0_cgroup,
-- Parent
pe.parent AS p1_pid,
p1.cgroup_path AS p1_cgroup,
TRIM(COALESCE(p1.cmdline, pe1.cmdline)) AS p1_cmd,
COALESCE(p1.path, pe1.path) AS p1_path,
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,
COALESCE(p1_p2.cgroup_path, pe1_p2.cgroup_path) AS p2_cgroup,
TRIM(
COALESCE(p1_p2.cmdline, pe1_p2.cmdline, pe1_pe2.cmdline)
) AS p2_cmd,
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 file ON pe.path = file.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') -60)
AND file.mode NOT LIKE '0%'
AND pe.env_size > 3500tags: SStagSS