Reworks the clusterer's tick to handle multi-identity components and
re-evaluate prior merges. Two passes per tick:
Pass 1 — per-component reconciliation:
* Fresh component → mint identity (commit 4 path).
* Single-identity component → link unassigned observations.
* Multi-identity component → soft-merge: pick the smallest-uuid
winner deterministically, set merged_into_uuid on each loser,
link unassigned observations to the winner. Observations stay
FK'd to their original identity row — the merge is a soft
pointer, not a re-point. Audit trail preserved; cached
subscribers resolve through the chain.
Pass 2 — revocable-merge undo:
* For each merged-out identity, check whether its observations
still cluster with its winner's. If not, the merge is
contradicted by new evidence — clear merged_into_uuid and emit
identities_unmerged. The resurrected identity keeps its original
uuid, so subscribers that cached it during the merged interval
re-attach without a new lookup.
A pre-built merge-chain dict feeds Pass 1 so the effective-identity
lookup is O(1) per observation. The chain has a hop cap (paranoia
against accidental cycles in the underlying state).
Repo additions on BaseRepository + SQLModelRepository:
* list_all_identities() — includes merged-out rows.
* update_identity_merged_into(uuid, winner_or_None) — single
setter for both merge and unmerge.
DummyRepo coverage stub updated.
Tests:
* Two distinct identities bridged by a new observation merge with
the smaller uuid as winner.
* A pre-seeded soft-merge whose underlying observations diverge
gets revoked; resurrected uuid emerges with merged_into_uuid
cleared.
* Tick is idempotent under no state changes.
Two operators cooperating on one campaign can share C2 endpoints +
stage-1 payloads while running distinct tooling — fixture 5
(multi_operator) is the canonical demonstration. The identity
clusterer must NOT fuse them: shared infra is a campaign-level
signal, not an identity-level one. The campaign clusterer (downstream
work) handles that grouping over identities.
Mechanism: when two observations have non-null fingerprints AND the
fingerprints fully disagree, the high-weight tier drops the payload
and C2 contributions to zero. JA3 / HASSH agreement still returns
1.0 directly — no veto applies when something agrees. Partial
agreement (one slot agrees, another disagrees) is treated as
agreement, since stable-tool partial overlap is more consistent
with one identity than two.
The veto only triggers when there is actual disagreement evidence —
two un-fingerprinted observations sharing a C2 still cluster, since
the absence of fingerprints is not the same as disagreement on them.
Fixture 5 production-clusterer assertion added at identity level:
ARI = 1.0, homogeneity = 1.0, exactly 2 predicted clusters from
2 truth identities. Phase-handoff edges (from the TODO) belong to
the downstream campaign clusterer, not this identity clusterer.
The clusterer now drops a single high-tier function call in favor of
a tier-weighted sum. Tier multipliers (high=1.0, medium=0.6, low=0.2,
very_low=0.05) are tuned so the threshold (1.0) admits high-tier
agreement alone while leaving every weaker tier — and every
combination of weaker tiers — under threshold.
Per-tier discipline tested:
- high alone clusters
- medium alone does NOT cluster (supporting signal only)
- low alone does NOT cluster (fixture 1's failure mode)
- very-low alone does NOT cluster (fixture 2's failure mode)
- all three weak tiers stacked still don't reach threshold
- high + medium clusters (high already saturates)
The combination is forward-compatible: low + very-low contributions
are computed today but always project to 0.0 because the production
adapter doesn't populate credentials / ASN-edge inputs into the
fixture path yet. Their contribution becomes load-bearing in commit 7
when the low-tier landing tightens the F1 / F2 bounds.
Fixture 4 (paused_campaign) ratchet added: high-tier signal carries
the multi-day-silence campaign into one identity. Time-agnostic
invariant — silence is irrelevant to the edge weight.
The connected-components clusterer now writes attacker_identities
rows + sets attackers.identity_id when high-weight signals (JA3 /
HASSH / payload-hash / C2-endpoint exact match) agree across
observations. Singletons stay un-fingerprinted and un-clustered.
Algorithm split:
- cluster_observations(observations) — pure union-find over the
high-weight edge function. Same code path for fixture validation
and production tick.
- from_attacker_row(row) — production-row adapter; recovers JA3 +
HASSH from Attacker.fingerprints JSON. Payload + C2 join from
logs in later commits; the function shape doesn't change.
Repo additions on BaseRepository + SQLModelRepository:
- list_attackers_for_clustering(limit=None)
- create_attacker_identity(row)
- set_attacker_identity_id(attacker_uuid, identity_uuid)
DummyRepo coverage stub updated.
v1 behavior is conservative: only assigns identities to observations
whose identity_id is currently NULL. Multi-identity components are
skipped this pass — merge / re-assign lands in commit 10 with
revocable merges.
Fixture bounds tightened against the production clusterer:
- lone_wolf (F3) — singletons stay singletons
- shared_wordlist (F1) — credential-only overlap doesn't cluster
(high-weight tier doesn't include credentials)
- vpn_hopping (F2, identity-level) — 5 rotated IPs with stable JA3
+ HASSH fold into one identity, ARI = 1.0, completeness = 1.0
Adds the four weight-tier edge functions as pure, time-agnostic
scoring primitives over an Observation projection. Each returns a
score in [0, 1]; the connected-components impl will combine + threshold
in subsequent commits.
Tier semantics (from IDENTITY_RESOLUTION.md):
- high — JA3/HASSH/payload-hash/C2-endpoint exact match
- medium — phase-bucketed command-sequence Jaccard
- low — credential-attempt-set Jaccard (defeated alone by F1)
- very low — ASN equality (defeated alone by F2)
Time-agnostic invariant is a static test: Observation has no time
fields, so no edge function can silently start using them. Fixture 7
forbids recency-decay clustering on multi-month APT campaigns.
A from_synthetic() adapter projects SyntheticAttacker corpora into
Observation; the production-row adapter lands when the clusterer
starts reading the attackers table.
Adds the decnet clusterer master-only command + provider-subpackage
shape (base.py + factory.py + impl/connected_components.py) so
subsequent commits can land similarity-graph features without
churning callers.
The skeleton ConnectedComponentsClusterer.tick is a no-op; the
worker shell is fully wired (bus consumer on attacker.observed +
attacker.scored, slow-tick fallback, health heartbeat, control
listener, ClusterResult fan-out to identity.formed/observation.linked
/merged). Subscribers on identity.> see no events from this clusterer
until edge functions land, but the lifecycle is in place.
