Files
acaua/README.md
T
Lucas RayanandClaude Sonnet 5 c64bbbf775 feat: implement Pillars 2-4 and fix a production false-positive in Pillar 1
Pillar 1 v1.1 (shipped earlier) flagged benign browsing bursts as
beaconing: on short captures, grid periods longer than the observed
span never complete a cycle, so significance saturates to 1 and the
score sticks at exactly 0.5. v1.2 caps the grid at a third of the
observed span, requires a minimum number of completed cycles, and
excludes protocols that are periodic by nature (NTP, DNS, mDNS,
ICMP). Validated against 300 seeds per scenario: false positives on
bursty traffic drop from the 290-300/300 that v1.1 produced to 0/300,
with every beacon-detection scenario scoring unchanged.

Add Pillar 2 (persistent/long-lived sessions, with Zeek's fragmented
TCP sessions rejoined after a 5-minute gap), Pillar 3 (DNS tunneling
via Shannon-entropy information volume per subdomain per hour; the
Jensen-Shannon divergence was measured and does not separate tunnels
from benign CDN subdomains, so it stays in the evidence at zero
weight instead of in the score), and Pillar 4 (deterministic
noisy-OR fusion across the three pillars).

The fusion formula was validated against 8 labeled real-traffic
vectors (IoT-23, CTU-Normal) with tolerance <= 1e-4. A known
limitation is kept, not hidden: a benign Philips HUE bulb's strict
periodic polling and a 21.9h session score it above three real C2
hosts. No weight or threshold was tuned to mask this; it is
documented in the architecture docs instead.

Also fixes real bugs found along the way: ingest_dir's partition
count summed file names instead of distinct dates, DuckDB errors
were counted as bad rows, /api/alerts always returned an empty list
regardless of the last analysis, and the dashboard still claimed
every pillar was unimplemented.

Restores four design corrections that were missing from
docs/architecture.md (KL to Jensen-Shannon, the persistent-session
detector, the JA4 licensing boundary, and deterministic reduction
order), and catalogs the public datasets used for validation
(IoT-23, CTU-Normal, Mendeley DTQBC) with their licenses and SHA-256
checksums under research/validation/.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VAyr8d7HuAdUGB6aA5xmDD
2026-11-01 00:28:54 -03:00

6.2 KiB
Raw Blame History

Acauã

Acauã

Deterministic network threat hunting.
Zeek-first NDR research · local-first · authorized use.

Terminal · Interface · Architecture · Docker · Support · Roadmap · Changelog

English · Português


Status: pre-release (initial version). The project structure, documentation, CI, Zeek ingestion for conn.log and dns.log, DuckDB/Parquet analytical storage, and initial versions of detection pillars 1 to 4 are implemented and validated against public traffic. Automatic continuous ingestion and cross-restart alert persistence are planned for upcoming releases.

Acauã is a network threat hunting engine built around deterministic evidence, not an opaque model. The goal is to answer not only "this looks suspicious" but "these exact inputs, with these intermediate values, produced this score".

  • Deterministic by design: fixed-order reductions, documented sentinels and a JSON evidence record for every future alert.
  • Local-first: the analytical store is embedded in the process; no external database and no telemetry by default.
  • Zeek-first: dns.log, ssl.log, conn.log and the protocol logs needed for identity and lateral-movement analysis. NetFlow/IPFIX is a documented degraded mode, never presented as equivalent. Suricata EVE JSON is an optional secondary input.
  • Server daemon and web dashboard: acaua serve runs continuous ingestion, scheduling, the API and the embedded web UI, distributed 100% via Docker.
  • Research stays outside the product: research/ is an isolated Python workspace for scientific validation and fixtures. It is never compiled, packaged or released.

What exists today

Area State
Rust workspace and CLI (acaua) ✅ functional
Axum API with health, status, alerts and analyze routes ✅ functional
Embedded web dashboard ✅ UI served by daemon
Documentation and CI/release workflows ✅
Docker multi-arch image and compose deployment ✅
DuckDB analytical store ✅ official prebuilt library linked
Four detection pillars (P1–P4) ✅ initial version
Zeek log parser (conn.log, dns.log) ✅ functional
Alert evidence and scoring ✅ deterministic JSON + noisy-OR fusion
Published releases ❌ none yet

The four pillars

All four pillars are implemented in their initial version (v1) and validated against synthetic fixtures and public captures:

  1. Beaconing (Pilar 1 v1.2): periodicity on event timestamps with a Rayleigh/Schuster periodogram bounded by the observed span, regularity significance gating, and infrastructure exclusions.
  2. Persistent sessions (Pilar 2 v1.0): long TCP connections chained across Zeek inactivity timeouts (up to 3600s gap without new SYN), log-scale persistence score, and PCR/failed attempt tracking.
  3. Protocol anomalies (Pilar 3 v1.0): deterministic information capacity (Shannon entropy \times unique subdomain characters per UTC hour) in DNS queries to detect tunneling.
  4. Evidence fusion (Pilar 4 v1.0): per-host weighted noisy-OR combination (w_1=w_2=w_3=0.75) with deterministic JSON evidence and ranking.

The design decisions behind these pillars, including the six corrections to the original blueprint, are in docs/architecture.md.

Authorized use

Acauã is defensive software for networks you own or are explicitly authorized to monitor. Capturing or analyzing third-party traffic without permission may be illegal. The operator is responsible for scope, privacy and retention.

The daemon binds to 127.0.0.1 by default. The Docker Compose deployment isolates the daemon in an unprivileged, read-only container with dropped capabilities.

Install

Run via Docker Compose (recommended for operators):

cp .env.example .env
docker compose pull && docker compose up -d

Or build and run locally with Docker:

docker compose up -d --build

To compile from source natively (Rust 1.88+ required):

scripts/fetch-libduckdb.sh ~/.cache/acaua/duckdb
export DUCKDB_LIB_DIR=~/.cache/acaua/duckdb LD_LIBRARY_PATH=~/.cache/acaua/duckdb
cargo build --release -p acaua-cli
./target/release/acaua --help

Supported platform matrix for published container images: linux/amd64 and linux/arm64.

Getting started

acaua doctor
acaua serve --bind 127.0.0.1:8787 --data-dir .acaua
acaua analyze /var/log/zeek/current --json
acaua update

analyze currently validates the directory and returns a skeleton report; it does not parse Zeek logs yet. serve exposes the stub API and the embedded web UI. update checks for new versions and guides container image updates.

Development

scripts/fetch-libduckdb.sh ~/.cache/acaua/duckdb
export DUCKDB_LIB_DIR=~/.cache/acaua/duckdb LD_LIBRARY_PATH=~/.cache/acaua/duckdb
cargo test --workspace
cargo clippy --workspace --all-targets
node scripts/check-ui-i18n.mjs
scripts/check.sh --full

See CONTRIBUTING.md and docs/architecture.md.

Known limits

  • The detection engine, Zeek parser and storage layer are stubs.
  • There is no published release image yet.
  • NetFlow/IPFIX is a degraded input mode by design; it cannot replace the Zeek protocol logs for every pillar.
  • The project targets Linux container environments (linux/amd64, linux/arm64).

Where it's going

Summary of the ROADMAP:

Done Workspace, CLI/API stubs, web dashboard, Docker containerization, CI/release workflows
Next Pillar 1 and 2 implementations with deterministic fixtures; real Zeek parser
Later Full Parquet partitioning, TTL pruning, pillar 3 and 4, evidence fusion
Not planned Opaque AI scoring, a required cloud service, Python in the shipped runtime

License

MIT or Apache-2.0, your choice.