Add egress drill + sid-verified harness and IR runbooks (roadmap v0.8)

Red-team harness: every detector now has a named drill with an expected
signature/sid, shown by `sentinel-redteam --list`. Add the missing
`egress` drill (the one detector without one) — explicit-only, since it
is the sole drill that emits real outbound traffic. After firing, the
harness runs `enodia-sentinel check` and reports PASS/MISS per poll
detection, turning it into a shared regression check.

Add docs/RUNBOOKS.md: confirm/preserve/contain/recover playbooks for
reverse shells & egress, persistence, trojaned binaries / package
tampering, hidden listeners & rootkits, and sensor tampering — each tied
to the real signatures, sids, and commands. Linked from README and the
OPERATIONS alert workflow.

Both close the remaining smaller v0.8 roadmap items.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
Luna 2026-06-10 05:28:53 -07:00
parent f2d896a2d7
commit 4015ec872b
5 changed files with 335 additions and 14 deletions

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@ -36,6 +36,8 @@ Project docs:
response, fleet, and assurance layers. response, fleet, and assurance layers.
- [Operations guide](docs/OPERATIONS.md) — install checks, health checks, alert - [Operations guide](docs/OPERATIONS.md) — install checks, health checks, alert
workflow, baseline hygiene, and evidence export. workflow, baseline hygiene, and evidence export.
- [IR runbooks](docs/RUNBOOKS.md) — confirm/preserve/contain/recover playbooks
per alert: reverse shells, persistence, trojaned binaries, rootkits, tampering.
> **Two implementations, on purpose.** The project began as a bash prototype > **Two implementations, on purpose.** The project began as a bash prototype
> (`src/sentinel.sh`, kept as the regression **oracle**) and was re-architected > (`src/sentinel.sh`, kept as the regression **oracle**) and was re-architected

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@ -96,7 +96,8 @@ When Sentinel fires:
cp -a /var/log/enodia-sentinel /tmp/enodia-sentinel-evidence cp -a /var/log/enodia-sentinel /tmp/enodia-sentinel-evidence
``` ```
7. Contain manually for now. Future response commands should produce a dry-run 7. Contain manually for now, following the matching playbook in
[RUNBOOKS.md](RUNBOOKS.md). Future response commands should produce a dry-run
plan first. plan first.
## Common Findings ## Common Findings

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@ -32,10 +32,10 @@ work that is bigger than single alerts.
package signatures. Still to come: unexpected enabled services and unsafe package signatures. Still to come: unexpected enabled services and unsafe
systemd unit settings. systemd unit settings.
- ✅ Add a machine-readable `status --json` command for automation. - ✅ Add a machine-readable `status --json` command for automation.
- Update the red-team harness so every current detection has a named drill and - Update the red-team harness so every current detection has a named drill and
expected `sid`. expected `sid` (`sentinel-redteam --list`), with a PASS/MISS verification pass.
- Document incident response runbooks for reverse shells, persistence, trojaned - Document incident response runbooks for reverse shells, persistence, trojaned
binaries, hidden listeners, and sensor tampering. binaries, hidden listeners, and sensor tampering ([RUNBOOKS.md](RUNBOOKS.md)).
Exit criteria: Exit criteria:

250
docs/RUNBOOKS.md Normal file
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@ -0,0 +1,250 @@
# Enodia Sentinel Incident Response Runbooks
Practical, conservative response playbooks for the alerts Sentinel raises. Each
runbook follows the same arc: **confirm → preserve → contain → recover**, and
prefers reversible, manual steps. Sentinel does not perform automatic
containment (see [THREAT_MODEL.md](THREAT_MODEL.md)); these are operator actions.
> A note on trust: if you suspect kernel-level compromise, remember that the
> tools you run (`ss`, `ps`, even `ls`) may be lying to you. Cross-check from the
> dashboard on another machine, and when in doubt, capture evidence and analyze
> the disk offline.
## The First Five Minutes
For any alert, before changing anything:
1. **Read the snapshot.** Every alert writes `alert-*.log` (human) and
`alert-*.json` (machine) under `/var/log/enodia-sentinel`. Note the
`signature`, `sid`, severity, PIDs, executable paths, and remote peers.
2. **Get host state.** `enodia-sentinel status` — is the daemon healthy, how many
alerts, when was the last.
3. **Triage known noise.** `enodia-sentinel triage` separates likely false
positives from findings that need a human.
4. **Preserve evidence before you touch anything:**
```bash
tar -C /var/log -czf /tmp/enodia-evidence-$(date +%s).tgz enodia-sentinel
```
Then pick the runbook below that matches the signature.
---
## Runbook 1 — Reverse shell / suspicious egress
**Triggers:** `reverse_shell` (sid 100010), `egress` (sid 100016).
An interpreter wired to a socket, or an interpreter holding a connection to a
public IP — the classic interactive-C2 and beaconing shapes.
**Confirm**
- Open the snapshot; identify the PID, `comm`, parent process, and remote peer.
- Inspect live (these views may be untrustworthy if root is compromised):
```bash
ps -o pid,ppid,user,comm,args -p <pid>
ls -l /proc/<pid>/fd # which fds are the socket
cat /proc/<pid>/environ | tr '\0' '\n'
ss -tnp | grep <pid> # the peer
```
- Is the peer expected? Compare against `egress_allow_cidrs` in config. A package
manager or browser to a public IP is normal; `bash`/`python`/`nc` is not.
**Contain**
- Capture the process before killing it (memory/maps if you have tooling), then:
`kill -STOP <pid>` to freeze, inspect, and only then `kill -9`.
- Block the peer if it is hostile: `nft add rule inet filter output ip daddr <peer> drop`.
- Find persistence the shell may have dropped — run Runbook 2.
**Recover**
- Rotate any credentials that were reachable from the compromised process.
- Rebuild listener/SUID baselines only after the host is confirmed clean.
**False positives:** legitimate admin scripts, monitoring agents, or P2P clients.
Add trusted egress destinations to `egress_allow_cidrs` rather than disabling the
detector.
---
## Runbook 2 — Persistence tampering
**Triggers:** `persistence` (sid 100015), `fim_modified` on a watched persistence
path.
A change to cron, a systemd unit, an SSH `authorized_keys`, a shell rc file, or
sudo/account config — how an attacker survives a reboot.
**Confirm**
- The snapshot names the changed path. Diff it against the FIM baseline and
package ownership:
```bash
enodia-sentinel fim-check
enodia-sentinel fim-check --packages # does a package own & vouch for it?
```
- For SSH keys: is the added key yours? For systemd/cron: does the unit run a
binary in a writable or unusual location?
**Contain**
- Remove the unauthorized entry (the added key, cron line, or unit). Keep a copy
in your evidence bundle first.
- `systemctl disable --now <unit>` for a malicious service; check what it spawned.
**Recover**
- After removing persistence, hunt for the process it launched (Runbook 1) and
any trojaned binaries (Runbook 3).
- Re-anchor the baseline only once clean: `enodia-sentinel fim-update`.
**False positives:** legitimate package upgrades and admin edits. The pacman hook
auto-runs `fim-update` for normal transactions; an unexplained change outside a
transaction is the suspicious case.
---
## Runbook 3 — Trojaned binary / package tampering
**Triggers:** `fim_modified` / `fim_pkg_modified` on a system binary,
`pkgdb_tamper` (package DB edited out of band), `pkg_signature_mismatch`
(on-disk file ≠ signed package), `pacman_siglevel_disabled`.
**Confirm**
- Layer the integrity checks from weakest to strongest trust anchor:
```bash
enodia-sentinel fim-check --packages # vs FIM baseline + pacman -Qkk
enodia-sentinel pkgdb-check # was the local checksum DB rewritten?
enodia-sentinel pkgdb-verify --sample 200 # vs signed cache packages (.MTREE)
```
- `pkg_signature_mismatch` is the strongest signal: it bypasses the mutable local
DB. Treat a mismatch on a system binary as a trojaned file until proven
otherwise. `pkgdb_tamper` suggests someone tried to hide exactly this.
**Contain**
- Do not execute the suspect binary. If it is currently running, freeze it
(Runbook 1).
- Confirm package-signature policy is intact: `enodia-sentinel posture check`
(flags `pacman_siglevel_disabled`).
**Recover**
- Identify the owning package and reinstall from a trusted source:
```bash
pacman -Qo /path/to/binary
pacman -S --overwrite '*' <package> # reinstall the verified file
enodia-sentinel fim-check --packages # confirm it now matches
```
- Then re-anchor: `enodia-sentinel fim-update` and re-run `pkgdb-check`.
**False positives:** a mid-upgrade snapshot can momentarily disagree. Re-run after
the transaction completes; a persistent mismatch is the real finding.
---
## Runbook 4 — Hidden listener / rootkit
**Triggers:** `rootkit_hidden_process` (100022), `rootkit_hidden_module` (100023),
`rootkit_hidden_port` (100024), `promiscuous_interface` (100025), and
`new_listener` (100013) for an unexplained open port.
These come from cross-view checks: the same question asked two ways, answered
differently, because something is hiding.
**Confirm**
- Re-run the cross-view sweep and capture it:
```bash
enodia-sentinel rootcheck
```
- `new_listener`: identify the owning process and whether its binary is
package-owned. A hidden port that `rootcheck` sees but `ss` does not is far more
serious than a forgotten service.
- A `rootkit_hidden_module` names a live kernel module absent from
`/proc/modules` — strong evidence of an LKM rootkit.
**Contain**
- Assume user-space tools are compromised. Pivot to the read-only dashboard from
**another machine** to cross-check, and prefer offline analysis.
- Do not `rmmod` blindly — capture the module and system state first.
**Recover**
- A confirmed kernel rootkit means **rebuild from known-good media**; you cannot
reliably clean a host whose kernel is hooked. Preserve the disk image first.
**False positives:** PID exit races (Sentinel re-verifies hidden PIDs to reduce
these) and a legitimately promiscuous interface (a sniffer/monitoring tool you
run). Confirm the owning process before escalating.
---
## Runbook 5 — Sensor tampering
**Triggers:** `fim_modified` on a Sentinel-owned path (self-integrity), a stale or
missing heartbeat surfaced by the off-box `watchdog`, or the dashboard going
unreachable.
Disabling the alarm is step zero of a competent intrusion — so a silent or
edited Sentinel is itself an alert.
**Confirm**
- From the **watchdog host** (never the protected host):
```bash
enodia-sentinel watchdog --url http://<host>:8787 --token <token> --max-age 120
```
Exit 1 means down, unreachable, or stale.
- On the host (if you still trust it): `enodia-sentinel status` and check whether
Sentinel's own binaries/config/units/hook changed:
```bash
enodia-sentinel fim-check # SELF_PATHS are always watched
```
**Contain**
- If Sentinel's files were edited, treat the host as compromised: an attacker with
the privilege to edit the sensor had the privilege to do far more.
- Move to evidence-preservation and offline analysis rather than trusting any
further local output.
**Recover**
- Reinstall Sentinel from a trusted source and re-baseline on a clean host.
- Harden against recurrence: `chattr +i` on Sentinel's binaries, config, units,
baselines, and the pacman hook; keep the watchdog running off-box.
**False positives:** a legitimate Sentinel upgrade changes its own files — but
that should coincide with a package transaction. An edit outside one is the
suspicious case.
---
## After any incident
- Keep the evidence bundle; do not delete snapshots while an investigation is open
(retention is bounded by `max_snapshots` / `max_snapshot_age_days`).
- Re-baseline (`baseline`, `fim-update`) only once the host is confirmed clean —
baselining a compromised host blesses the compromise.
- Re-run `enodia-sentinel posture check` to close the hygiene gaps that enabled
the intrusion.
- The incident-grouping commands (`incident show/export`) on the
[roadmap](ROADMAP.md) will eventually automate the evidence-bundle steps above.

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@ -8,11 +8,13 @@
# everything is cleaned up on exit. # everything is cleaned up on exit.
# #
# Usage: # Usage:
# sentinel-redteam run all drills (default 20s each window) # sentinel-redteam run the default drills (20s each window)
# sentinel-redteam <name>... run only the named drills # sentinel-redteam <name>... run only the named drills
# sentinel-redteam --list list available drills # sentinel-redteam --list list drills with their expected detector + sid
# #
# Drills: reverse_shell ld_preload deleted_exe new_listener new_suid persistence # Every current detector has a named drill with an expected signature/sid (see
# --list), so this doubles as a shared regression suite: after firing, it runs
# `enodia-sentinel check` and reports PASS/MISS for each poll detection.
# #
# Watch it work, in another terminal: # Watch it work, in another terminal:
# sudo tail -f /var/log/enodia-sentinel/events.log # sudo tail -f /var/log/enodia-sentinel/events.log
@ -25,6 +27,24 @@ TMP="$(mktemp -d /tmp/enodia-drill.XXXXXX)"
PIDS=() PIDS=()
SANDBOX="$TMP/persistence-sandbox" # used by the persistence drill SANDBOX="$TMP/persistence-sandbox" # used by the persistence drill
LISTEN_PORT=14444 LISTEN_PORT=14444
# egress drill target — the ONE drill that makes a real outbound connection.
EGRESS_HOST="${EGRESS_HOST:-1.1.1.1}"
EGRESS_PORT="${EGRESS_PORT:-53}"
# Drill metadata: name -> "signature sid kind", where kind is how it's verified:
# poll = the one-shot `check` should catch it
# event = only the eBPF monitor sees it (vanishes between polls)
# cond = conditional (needs extra setup; see the drill's note)
declare -A DRILL_SIG=(
[reverse_shell]="reverse_shell 100010 poll"
[ld_preload]="ld_preload 100011 poll"
[deleted_exe]="deleted_exe 100012 poll"
[new_listener]="new_listener 100013 poll"
[new_suid]="new_suid 100014 poll"
[persistence]="persistence 100015 cond"
[egress]="egress 100016 poll"
[ebpf_exec]="exec_anomaly 100001/100002 event"
)
cleanup() { cleanup() {
echo "[*] cleaning up drill artifacts..." echo "[*] cleaning up drill artifacts..."
@ -110,6 +130,22 @@ drill_persistence() {
echo " -> wrote $SANDBOX/authorized_keys" echo " -> wrote $SANDBOX/authorized_keys"
} }
drill_egress() {
note egress "an interpreter (python) holding an outbound TCP connection to a public IP"
echo " WARNING: unlike the other drills, this makes ONE real outbound TCP"
echo " connection to a public host (${EGRESS_HOST}:${EGRESS_PORT}). No data is sent;"
echo " only the handshake. Set EGRESS_HOST/EGRESS_PORT to retarget, or skip it."
# python3 is an 'interpreter' to the egress detector; an established socket
# to a globally-routable IP is exactly the C2/exfil shape it flags (sid 100016).
python3 -c 'import socket,sys,time
s=socket.socket()
try:
s.connect((sys.argv[1], int(sys.argv[2]))); time.sleep(int(sys.argv[3]))
except Exception: pass' "$EGRESS_HOST" "$EGRESS_PORT" "$HOLD" >/dev/null 2>&1 &
PIDS+=("$!")
echo " -> python3 (pid $!) connected to ${EGRESS_HOST}:${EGRESS_PORT} for ${HOLD}s"
}
drill_ebpf_exec() { drill_ebpf_exec() {
note ebpf_exec "short-lived /tmp exec + reverse-shell-pattern argv (only the eBPF monitor catches these)" note ebpf_exec "short-lived /tmp exec + reverse-shell-pattern argv (only the eBPF monitor catches these)"
cp /bin/true "$TMP/enodia-drill-exec" 2>/dev/null cp /bin/true "$TMP/enodia-drill-exec" 2>/dev/null
@ -130,14 +166,29 @@ run() {
new_listener) drill_new_listener ;; new_listener) drill_new_listener ;;
new_suid) drill_new_suid ;; new_suid) drill_new_suid ;;
persistence) drill_persistence ;; persistence) drill_persistence ;;
egress) drill_egress ;;
ebpf_exec) drill_ebpf_exec ;; ebpf_exec) drill_ebpf_exec ;;
*) echo "unknown drill: $1" >&2; return 1 ;; *) echo "unknown drill: $1" >&2; return 1 ;;
esac esac
} }
# egress is excluded from the default run because it is the only drill that
# emits real network traffic; name it explicitly to include it.
ALL=(reverse_shell ld_preload deleted_exe new_listener new_suid persistence ebpf_exec) ALL=(reverse_shell ld_preload deleted_exe new_listener new_suid persistence ebpf_exec)
KNOWN=(reverse_shell ld_preload deleted_exe new_listener new_suid persistence egress ebpf_exec)
if [ "${1:-}" = "--list" ]; then printf '%s\n' "${ALL[@]}"; exit 0; fi if [ "${1:-}" = "--list" ]; then
printf '%-15s %-16s %-7s %s\n' DRILL SIGNATURE SID KIND
for d in "${KNOWN[@]}"; do
read -r sig sid kind <<<"${DRILL_SIG[$d]}"
printf '%-15s %-16s %-7s %s\n' "$d" "$sig" "$sid" "$kind"
done
echo
echo "kinds: poll=caught by 'check'; event=eBPF-only; cond=needs extra setup"
echo "note: rootcheck (100022-25) and posture (100040-47) are verified by"
echo " 'enodia-sentinel rootcheck' / 'posture check', not attack drills."
exit 0
fi
echo "######################################################################" echo "######################################################################"
echo "# ENODIA SENTINEL — RED TEAM DRILL #" echo "# ENODIA SENTINEL — RED TEAM DRILL #"
@ -148,14 +199,31 @@ echo "######################################################################"
if [ "$#" -gt 0 ]; then targets=("$@"); else targets=("${ALL[@]}"); fi if [ "$#" -gt 0 ]; then targets=("$@"); else targets=("${ALL[@]}"); fi
for d in "${targets[@]}"; do run "$d"; done for d in "${targets[@]}"; do run "$d"; done
echo -e "\n[*] drills live for ${HOLD}s. Run a one-shot poll check now:" # --- verification: run one poll check and confirm each expected signature ----
echo -e "\n[*] drills live for ${HOLD}s. Verifying with a one-shot poll check..."
if command -v enodia-sentinel >/dev/null 2>&1; then if command -v enodia-sentinel >/dev/null 2>&1; then
enodia-sentinel check 2>/dev/null | grep -i 'drill\|/tmp/enodia' \ sleep 1
&& echo " ^ Sentinel's poll detectors saw the drills." \ OUT="$(enodia-sentinel check 2>/dev/null)"
|| echo " (no poll hits yet — watch /var/log/enodia-sentinel/events.log)" pass=0; miss=0
for d in "${targets[@]}"; do
read -r sig sid kind <<<"${DRILL_SIG[$d]}"
case "$kind" in
poll)
if grep -qw "$sig" <<<"$OUT"; then
printf ' PASS %-15s %s (sid %s)\n' "$d" "$sig" "$sid"; pass=$((pass+1))
else
printf ' MISS %-15s expected %s (sid %s)\n' "$d" "$sig" "$sid"; miss=$((miss+1))
fi ;;
event)
printf ' INFO %-15s %s — eBPF-only; see events.log (sid %s)\n' "$d" "$sig" "$sid" ;;
cond)
printf ' INFO %-15s %s — conditional; see the drill note (sid %s)\n' "$d" "$sig" "$sid" ;;
esac
done
echo " ---- ${pass} passed, ${miss} missed (poll detections) ----"
[ "$miss" -gt 0 ] && echo " MISS can be a real regression OR a timing/baseline gap — re-check events.log."
else else
echo " (enodia-sentinel not on PATH — watch /var/log/enodia-sentinel/events.log)" echo " (enodia-sentinel not on PATH — watch /var/log/enodia-sentinel/events.log)"
fi fi
echo " The 'ebpf_exec' drill only shows up with the eBPF monitor (service as root)."
echo "[*] holding for ${HOLD}s, then cleaning up..." echo "[*] holding for ${HOLD}s, then cleaning up..."
sleep "$HOLD" sleep "$HOLD"