Found during live testing: netdata's cloud-provider auto-detection runs
curl --fail -s -m1 --noproxy * http://169.254.169.254 on every
startup/reconnect to check whether the host is in AWS/GCP/Azure - standard
monitoring-agent behavior, not a bug. Without this exception the rule
would have paged every time netdata restarts. Scoped to netdata's own
curl specifically so any other connection from that container still
alerts.
git-hook-tamper.yaml's condition used proc.exepath, which resolves to the
script interpreter's path (e.g. /bin/busybox) for shebang scripts, not the
script's own path - switched to proc.cmdline, which retains the originally
invoked path. Confirmed via live-testing both ways.
ssh-persistence/cloud-metadata-probe/db-spawned-process round out the
post-incident hardening pass with a few more incubating-ruleset adaptations.
Written after the 2026-08-10/11 gitea internal-API log-poisoning attack
that planted a malicious uploadpack.packObjectsHook backdoor. Catches
both the planting (unexpected exec from a hooks/ path) and the firing
(git-upload-pack/git-receive-pack spawning anything but its own
pack-objects binary), independent of how the hook config got written.
No repeat intrusion - investigated all Falco alerts since deployment
(2026-08-08 to 2026-08-16); the only crypto-miner rule hits were the
original test alerts. The daily self-resolving Telegram alerts the user
was seeing came from four known-benign sources: Obsidian's Electron
self-re-exec pattern and s6-init sudoers setup (fires ~daily on container
recreation), ttyd/Synchronet's telnet/pv/busybox-extras BBS tooling, and
ollama's nvidia-ctk ldconfig-refresh hook (memfd_create by design). Added
scoped exceptions for each via Falco's own rule extension points, same
pattern as the earlier pg_isready/gitea fixes.
Also fixed netdata's used_swap alarm, which recalculated from the
instantaneous raw sample every 10s with only a 30s notification debounce -
a brief swap spike was enough to page both Telegram and (via Netdata
Cloud) email. Widened the up-delay to 5m so only sustained swap pressure
notifies.
Verified end-to-end via a fresh fake-xmrig test after redeploying Falco
and reloading netdata: CRITICAL alarm fired and Telegram delivery
succeeded.
- 'Drop and execute new binary in container' fired on every git push/pull
to gitea over SSH (gitea's own binary re-executing itself for git-shell
hooks looks like container drift). Scoped exception via
known_drop_and_execute_activities to proc.name=gitea on that specific
image, not a blanket container whitelist, so other unexpected binaries
in that container still get caught.
- netdata alarm text was a static generic blurb requiring a manual
'docker logs falco' every time to find out what actually happened.
Now interpolates ${label:rule_name}/${label:priority} (exposed by
Falco's Prometheus metric) so the Telegram message names the specific
rule directly. Note: literal double-quotes in the info/summary text
broke netdata's alarm-notify.sh (silent delivery failure, exit 1) -
avoided.
- Added netdata/health.d and netdata/go.d to the repo for documentation;
netdata does not auto-deploy these from git, same as gitea's app.ini -
copy to /srv/netdata/config/ manually and restart the container.
Detects unauthorized miners (and other runtime threats) via Falco's
syscall/eBPF monitoring, following the 2026-08-06 gitea/xmrig
compromise. Wired into netdata rather than a new notification channel:
Falco exposes a Prometheus /metrics endpoint, netdata scrapes it, and a
new health.d alarm pages through netdata's already-configured Telegram
bot - no new alerting infra needed.
Includes a custom process-name rule for known miner binaries (the stock
Stratum-protocol rule wouldn't have caught the actual gitea incident,
which used a bare host:port with no scheme prefix), an outbound
miner-pool-port rule as a second layer, and rule_matching: all in the
Falco config - without it, Falco silently drops all but the first
matching rule per event, which would have suppressed our custom rule
whenever a stock rule also matched the same process.
poprhythm