osquery-defense-kit/detection/privesc/unexpected-elevated-childre...

62 lines
2.0 KiB
SQL

-- Find processes that run with a lower effective UID than their parent (event-based)
--
-- references:
-- * https://attack.mitre.org/techniques/T1548/001/ (Setuid and Setgid)
-- * https://cybersecurity.att.com/blogs/labs-research/shikitega-new-stealthy-malware-targeting-linux
--
-- related:
-- * unexpected-privilege-escalation.sql
--
-- tags: events process escalation
-- platform: darwin
-- interval: 30
SELECT
p.pid AS child_pid,
p.path AS child_path,
REGEX_MATCH (RTRIM(file.path, '/'), '.*/(.*?)$', 1) AS child_name,
p.cmdline AS child_cmdline,
p.time,
pp.start_time,
p.euid AS child_euid,
file.mode AS child_mode,
hash.sha256 AS child_hash,
p.parent AS parent_pid,
pp.path AS parent_path,
pp.name AS parent_name,
pp.cmdline AS parent_cmdline,
pp.euid AS parent_euid,
pfile.mode AS parent_mode,
phash.sha256 AS parent_hash
FROM
process_events p
JOIN processes pp ON p.parent = pp.pid
LEFT JOIN file ON p.path = file.path
LEFT JOIN hash ON p.path = hash.path
LEFT JOIN file AS pfile ON pp.path = pfile.path
LEFT JOIN hash AS phash ON pp.path = phash.path
WHERE
p.time > (strftime('%s', 'now') -30)
AND p.euid < pp.euid
AND p.path NOT IN (
'/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/Metadata.framework/Versions/A/Support/mdworker_shared',
'/usr/bin/login',
'/usr/bin/su',
'/usr/bin/sudo',
'/usr/local/bin/doas'
)
-- Exclude weird bad data we've seen due to badly recorded macOS parent/child relationships, fixable by reboot
AND NOT (
p.cmdline IN (
'/usr/sbin/cupsd -l',
'/usr/libexec/mdmclient daemon',
'/System/Library/Frameworks/CoreServices.framework/Frameworks/Metadata.framework/Versions/A/Support/mdworker_shared -s mdworker -c MDSImporterWorker -m com.apple.mdworker.shared'
)
)
-- More very weird data that keeps showing up: gopls starting everything!
-- I think this may be due to some bad joining
AND NOT (
pp.cmdline LIKE '%/go/bin/gopls -mode=stdio'
AND pp.path LIKE '/Users/%/go/bin/gopls'
AND pp.euid > 500
)