mirror of
https://github.com/chainguard-dev/osquery-defense-kit
synced 2024-12-15 18:44:32 +00:00
90 lines
2.9 KiB
SQL
90 lines
2.9 KiB
SQL
-- Catch DNS traffic going to machines other than the host-configured DNS server (event-based)
|
|
--
|
|
-- references:
|
|
-- * https://attack.mitre.org/techniques/T1071/004/ (C2: Application Layer Protocol: DNS)
|
|
--
|
|
-- interval: 120
|
|
-- tags: persistent events net
|
|
--
|
|
-- NOTE: The interval above must match WHERE clause to avoid missing events
|
|
--
|
|
-- This only supports IPv4 traffic due to an osquery bug with 'dns_resolvers'
|
|
-- The non-event version is unexpected-dns-traffic.sql
|
|
SELECT
|
|
protocol,
|
|
s.remote_port,
|
|
s.remote_address,
|
|
p.name,
|
|
p.path,
|
|
p.cmdline AS child_cmd,
|
|
p.cwd,
|
|
s.pid,
|
|
p.parent AS parent_pid,
|
|
pp.cmdline AS parent_cmd,
|
|
hash.sha256,
|
|
CONCAT (p.name, ',', remote_address, ',', remote_port) AS exception_key
|
|
FROM
|
|
socket_events s
|
|
LEFT JOIN processes p ON s.pid = p.pid
|
|
LEFT JOIN processes pp ON p.parent = pp.pid
|
|
LEFT JOIN hash ON p.path = hash.path
|
|
WHERE
|
|
s.time > (strftime('%s', 'now') -120)
|
|
AND remote_port IN (53, 5353)
|
|
AND remote_address NOT LIKE '%:%'
|
|
AND s.remote_address NOT LIKE '172.1%'
|
|
AND s.remote_address NOT LIKE '172.2%'
|
|
AND s.remote_address NOT LIKE '172.30.%'
|
|
AND s.remote_address NOT LIKE '172.31.%'
|
|
AND s.remote_address NOT LIKE '10.%'
|
|
AND s.remote_address NOT LIKE '192.168.%'
|
|
AND s.remote_address NOT LIKE '127.%'
|
|
AND remote_address NOT IN (
|
|
SELECT DISTINCT
|
|
address
|
|
FROM
|
|
dns_resolvers
|
|
WHERE
|
|
type = 'nameserver'
|
|
and address != ''
|
|
)
|
|
-- systemd-resolve sometimes shows up this way
|
|
-- If we could narrow this down using 'sys_resolvers' I would, but it is misuse of GROUP_CONCAT
|
|
AND NOT (
|
|
s.pid = -1
|
|
AND s.remote_port = 53
|
|
and p.parent = ''
|
|
)
|
|
-- Some applications hard-code a safe DNS resolver, or allow the user to configure one
|
|
AND s.remote_address NOT IN (
|
|
'1.1.1.1', -- Cloudflare
|
|
'1.1.1.2', -- Cloudflare
|
|
'8.8.8.8', -- Google
|
|
'8.8.4.4', -- Google (backup)
|
|
'208.67.222.222', -- OpenDNS
|
|
'75.75.75.75', -- Comcast
|
|
'75.75.76.76', -- Comcast
|
|
'68.105.28.13' -- Cox
|
|
)
|
|
-- Exceptions that specifically talk to one server
|
|
AND exception_key NOT IN (
|
|
'coredns,0.0.0.0,53',
|
|
'syncthing,46.162.192.181,53',
|
|
'Jabra Direct Helper,208.67.222.123,53'
|
|
)
|
|
AND p.name != 'nessusd'
|
|
-- Local DNS servers and custom clients go here
|
|
AND p.path NOT IN (
|
|
'/usr/lib/systemd/systemd-resolved',
|
|
'/Library/Nessus/run/sbin/nessusd',
|
|
'/Applications/Slack.app/Contents/Frameworks/Slack Helper.app/Contents/MacOS/Slack Helper',
|
|
'/Applications/Spotify.app/Contents/Frameworks/Spotify Helper.app/Contents/MacOS/Spotify Helper'
|
|
)
|
|
AND p.path NOT LIKE '/Applications/Google Chrome.app/Contents/Frameworks/Google Chrome Framework.framework/Versions/%/Helpers/Google Chrome Helper.app/Contents/MacOS/Google Chrome Helper'
|
|
-- Workaround for the GROUP_CONCAT subselect adding a blank ent
|
|
GROUP BY
|
|
s.remote_address,
|
|
s.remote_port
|
|
HAVING
|
|
remote_address != ''
|