osquery-defense-kit/detection/execution/unexpected-file-made-executable.sql
2023-05-16 17:18:39 -04:00

80 lines
2.7 KiB
SQL

-- Detect commands used to bless a file as executable
--
-- false positives:
-- * none observed, but they are expected
--
-- interval: 600
-- platform: posix
-- tags: process events
SELECT
-- Child
pe.path AS p0_path,
REGEX_MATCH (pe.path, '.*/(.*)', 1) AS p0_name,
TRIM(pe.cmdline) AS p0_cmd,
pe.cwd AS p0_cwd,
pe.time AS p0_time,
pe.euid AS p0_euid,
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,
-- Extra fields
REGEX_MATCH (TRIM(pe.cmdline), ".* (.*?)$", 1) AS target_path
FROM
process_events pe,
uptime
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') -600)
AND pe.cmdline != ''
AND pe.path IN ('/bin/chmod', '/usr/bin/chmod')
AND (
p0_cmd LIKE '%chmod 7%'
OR p0_cmd LIKE '%chmod 5%'
OR p0_cmd LIKE '%chmod 1%'
OR p0_cmd LIKE '%chmod +%x'
)
AND p0_cmd NOT LIKE 'chmod 700 /tmp/apt-key-gpghome.%'
AND p0_cmd NOT LIKE 'chmod 700 /home/%/snap/%/.config'
AND p0_cmd NOT LIKE 'chmod 755 /home/%/.gradle/wrapper/dists/gradle-%-bin/%bin/gradle'
AND p0_cmd NOT IN ('chmod 755 /usr/local/share/ca-certificates')
AND NOT p0_cgroup LIKE '/system.slice/docker-%'
GROUP BY
pe.pid