refactor(profiler): split behavioral.py into topical modules

Break the 603-line behavioral.py into timing/classify/tools/phases/fingerprint
sibling modules plus a slim orchestrator. Public API unchanged: behavioral.py
re-exports every previously-exposed symbol, so worker.py and existing tests
keep working with zero import changes.

No behavior change; all 64 profiler tests pass.
This commit is contained in:
2026-04-22 21:10:19 -04:00
parent b51095cec5
commit 25838eb9f3
6 changed files with 575 additions and 526 deletions

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"""
Behavioral and timing analysis for DECNET attacker profiles.
Consumes the chronological `LogEvent` stream already built by
`decnet.correlation.engine.CorrelationEngine` and derives per-IP metrics:
This module is the orchestrator: it composes the topical sub-modules
(`timing`, `classify`, `tools`, `phases`, `fingerprint`) into the single
`attacker_behavior` record persisted by the profiler worker.
- Inter-event timing statistics (mean / median / stdev / min / max)
- Coefficient-of-variation (jitter metric)
- Beaconing vs. interactive vs. scanning vs. brute_force vs. slow_scan
classification
- Tool attribution against known C2 frameworks (Cobalt Strike, Sliver,
Havoc, Mythic) using default beacon/jitter profiles — returns a list,
since multiple tools can be in use simultaneously
- Header-based tool detection (Nmap NSE, Gophish, Nikto, sqlmap, etc.)
from HTTP request events
- Recon → exfil phase sequencing (latency between the last recon event
and the first exfil-like event)
- OS / TCP fingerprint + retransmit rollup from sniffer-emitted events,
with TTL-based fallback when p0f returns no match
The individual detectors live in sibling modules:
- `timing.py` — inter-arrival-time statistics
- `classify.py` — behavior bucket (beaconing / scanning / …)
- `tools.py` — C2 beacon cadence + HTTP-header tool attribution
- `phases.py` — recon → exfil phase sequencing
- `fingerprint.py` — sniffer + prober TCP/OS fingerprint rollup
Pure-Python; no external dependencies. All functions are safe to call from
both sync and async contexts.
Their public symbols are re-exported here for backward compatibility with
callers and tests that import directly from `decnet.profiler.behavioral`.
"""
from __future__ import annotations
import json
import re
import statistics
from collections import Counter
from typing import Any
from decnet.correlation.parser import LogEvent
from decnet.telemetry import traced as _traced, get_tracer as _get_tracer
# ─── Event-type taxonomy ────────────────────────────────────────────────────
from .classify import classify_behavior
from .fingerprint import sniffer_rollup
from .phases import phase_sequence
from .timing import timing_stats
from .tools import detect_tools_from_headers, guess_tool, guess_tools
__all__ = [
"build_behavior_record",
"classify_behavior",
"detect_tools_from_headers",
"guess_tool",
"guess_tools",
"phase_sequence",
"sniffer_rollup",
"timing_stats",
]
# Sniffer-emitted packet events that feed into fingerprint rollup.
_SNIFFER_SYN_EVENT: str = "tcp_syn_fingerprint"
_SNIFFER_FLOW_EVENT: str = "tcp_flow_timing"
# Prober-emitted active-probe result (SYN-ACK fingerprint of attacker machine).
_PROBER_TCPFP_EVENT: str = "tcpfp_fingerprint"
# Canonical initial TTL for each coarse OS bucket. Used to derive hop
# distance when only the observed TTL is available (prober path).
_INITIAL_TTL: dict[str, int] = {
"linux": 64,
"windows": 128,
"embedded": 255,
}
# Events that signal "recon" phase (scans, probes, auth attempts).
_RECON_EVENT_TYPES: frozenset[str] = frozenset({
"scan", "connection", "banner", "probe",
"login_attempt", "auth", "auth_failure",
})
# Events that signal "exfil" / action-on-objective phase.
_EXFIL_EVENT_TYPES: frozenset[str] = frozenset({
"download", "upload", "file_transfer", "data_exfil",
"command", "exec", "query", "shell_input",
})
# Fields carrying payload byte counts (for "large payload" detection).
_PAYLOAD_SIZE_FIELDS: tuple[str, ...] = ("bytes", "size", "content_length")
# ─── C2 tool attribution signatures (beacon timing) ─────────────────────────
#
# Each entry lists the default beacon cadence profile of a popular C2.
# A profile *matches* an attacker when:
# - mean inter-event time is within ±`interval_tolerance` seconds, AND
# - jitter (cv = stdev / mean) is within ±`jitter_tolerance`
#
# Multiple matches are all returned (attacker may run multiple implants).
_TOOL_SIGNATURES: tuple[dict[str, Any], ...] = (
{
"name": "cobalt_strike",
"interval_s": 60.0,
"interval_tolerance_s": 8.0,
"jitter_cv": 0.20,
"jitter_tolerance": 0.05,
},
{
"name": "sliver",
"interval_s": 60.0,
"interval_tolerance_s": 10.0,
"jitter_cv": 0.30,
"jitter_tolerance": 0.08,
},
{
"name": "havoc",
"interval_s": 45.0,
"interval_tolerance_s": 8.0,
"jitter_cv": 0.10,
"jitter_tolerance": 0.03,
},
{
"name": "mythic",
"interval_s": 30.0,
"interval_tolerance_s": 6.0,
"jitter_cv": 0.15,
"jitter_tolerance": 0.03,
},
)
# ─── Header-based tool signatures ───────────────────────────────────────────
#
# Scanned against HTTP `request` events. `pattern` is a case-insensitive
# substring (or a regex anchored with ^ if it starts with that character).
# `header` is matched case-insensitively against the event's headers dict.
_HEADER_TOOL_SIGNATURES: tuple[dict[str, str], ...] = (
{"name": "nmap", "header": "user-agent", "pattern": "Nmap Scripting Engine"},
{"name": "gophish", "header": "x-mailer", "pattern": "gophish"},
{"name": "nikto", "header": "user-agent", "pattern": "Nikto"},
{"name": "sqlmap", "header": "user-agent", "pattern": "sqlmap"},
{"name": "nuclei", "header": "user-agent", "pattern": "Nuclei"},
{"name": "masscan", "header": "user-agent", "pattern": "masscan"},
{"name": "zgrab", "header": "user-agent", "pattern": "zgrab"},
{"name": "metasploit", "header": "user-agent", "pattern": "Metasploit"},
{"name": "curl", "header": "user-agent", "pattern": "^curl/"},
{"name": "python_requests", "header": "user-agent", "pattern": "python-requests"},
{"name": "gobuster", "header": "user-agent", "pattern": "gobuster"},
{"name": "dirbuster", "header": "user-agent", "pattern": "DirBuster"},
{"name": "hydra", "header": "user-agent", "pattern": "hydra"},
{"name": "wfuzz", "header": "user-agent", "pattern": "Wfuzz"},
)
# ─── TTL → coarse OS bucket (fallback when p0f returns nothing) ─────────────
def _os_from_ttl(ttl_str: str | None) -> str | None:
"""Derive a coarse OS guess from observed TTL when p0f has no match."""
if not ttl_str:
return None
try:
ttl = int(ttl_str)
except (TypeError, ValueError):
return None
if 55 <= ttl <= 70:
return "linux"
if 115 <= ttl <= 135:
return "windows"
if 235 <= ttl <= 255:
return "embedded"
return None
# ─── Timing stats ───────────────────────────────────────────────────────────
@_traced("profiler.timing_stats")
def timing_stats(events: list[LogEvent]) -> dict[str, Any]:
"""
Compute inter-arrival-time statistics across *events* (sorted by ts).
Returns a dict with:
mean_iat_s, median_iat_s, stdev_iat_s, min_iat_s, max_iat_s, cv,
event_count, duration_s
For n < 2 events the interval-based fields are None/0.
"""
if not events:
return {
"event_count": 0,
"duration_s": 0.0,
"mean_iat_s": None,
"median_iat_s": None,
"stdev_iat_s": None,
"min_iat_s": None,
"max_iat_s": None,
"cv": None,
}
sorted_events = sorted(events, key=lambda e: e.timestamp)
duration_s = (sorted_events[-1].timestamp - sorted_events[0].timestamp).total_seconds()
if len(sorted_events) < 2:
return {
"event_count": len(sorted_events),
"duration_s": round(duration_s, 3),
"mean_iat_s": None,
"median_iat_s": None,
"stdev_iat_s": None,
"min_iat_s": None,
"max_iat_s": None,
"cv": None,
}
iats = [
(sorted_events[i].timestamp - sorted_events[i - 1].timestamp).total_seconds()
for i in range(1, len(sorted_events))
]
# Exclude spuriously-negative (clock-skew) intervals.
iats = [v for v in iats if v >= 0]
if not iats:
return {
"event_count": len(sorted_events),
"duration_s": round(duration_s, 3),
"mean_iat_s": None,
"median_iat_s": None,
"stdev_iat_s": None,
"min_iat_s": None,
"max_iat_s": None,
"cv": None,
}
mean = statistics.fmean(iats)
median = statistics.median(iats)
stdev = statistics.pstdev(iats) if len(iats) > 1 else 0.0
cv = (stdev / mean) if mean > 0 else None
return {
"event_count": len(sorted_events),
"duration_s": round(duration_s, 3),
"mean_iat_s": round(mean, 3),
"median_iat_s": round(median, 3),
"stdev_iat_s": round(stdev, 3),
"min_iat_s": round(min(iats), 3),
"max_iat_s": round(max(iats), 3),
"cv": round(cv, 4) if cv is not None else None,
}
# ─── Behavior classification ────────────────────────────────────────────────
@_traced("profiler.classify_behavior")
def classify_behavior(stats: dict[str, Any], services_count: int) -> str:
"""
Coarse behavior bucket:
beaconing | interactive | scanning | brute_force | slow_scan | mixed | unknown
Heuristics (evaluated in priority order):
* `scanning` — ≥ 3 services touched OR mean IAT < 2 s, ≥ 3 events
* `brute_force` — 1 service, n ≥ 8, mean IAT < 5 s, CV < 0.6
* `beaconing` — CV < 0.35, mean IAT ≥ 5 s, ≥ 4 events
* `slow_scan` — ≥ 2 services, mean IAT ≥ 10 s, ≥ 4 events
* `interactive` — mean IAT < 5 s AND CV ≥ 0.5, ≥ 6 events
* `mixed` — catch-all for sessions with enough data
* `unknown` — too few data points
"""
n = stats.get("event_count") or 0
mean = stats.get("mean_iat_s")
cv = stats.get("cv")
if n < 3 or mean is None:
return "unknown"
# Slow scan / low-and-slow: multiple services with long gaps.
# Must be checked before generic scanning so slow multi-service sessions
# don't get mis-bucketed as a fast sweep.
if services_count >= 2 and mean >= 10.0 and n >= 4:
return "slow_scan"
# Scanning: broad service sweep (multi-service) or very rapid single-service bursts.
if n >= 3 and (
(services_count >= 3 and mean < 10.0)
or (services_count >= 2 and mean < 2.0)
):
return "scanning"
# Brute force: hammering one service rapidly and repeatedly.
if services_count == 1 and n >= 8 and mean < 5.0 and cv is not None and cv < 0.6:
return "brute_force"
# Beaconing: regular cadence over multiple events.
if cv is not None and cv < 0.35 and mean >= 5.0 and n >= 4:
return "beaconing"
# Interactive: short but irregular bursts (human or tool with think time).
if cv is not None and cv >= 0.5 and mean < 5.0 and n >= 6:
return "interactive"
return "mixed"
# ─── C2 tool attribution (beacon timing) ────────────────────────────────────
def guess_tools(mean_iat_s: float | None, cv: float | None) -> list[str]:
"""
Match (mean_iat, cv) against known C2 default beacon profiles.
Returns a list of all matching tool names (may be empty). Multiple
matches are all returned because an attacker can run several implants.
"""
if mean_iat_s is None or cv is None:
return []
hits: list[str] = []
for sig in _TOOL_SIGNATURES:
if abs(mean_iat_s - sig["interval_s"]) > sig["interval_tolerance_s"]:
continue
if abs(cv - sig["jitter_cv"]) > sig["jitter_tolerance"]:
continue
hits.append(sig["name"])
return hits
# Keep the old name as an alias so callers that expected a single string still
# compile, but mark it deprecated. Returns the first hit or None.
def guess_tool(mean_iat_s: float | None, cv: float | None) -> str | None:
"""Deprecated: use guess_tools() instead."""
hits = guess_tools(mean_iat_s, cv)
if len(hits) == 1:
return hits[0]
return None
# ─── Header-based tool detection ────────────────────────────────────────────
@_traced("profiler.detect_tools_from_headers")
def detect_tools_from_headers(events: list[LogEvent]) -> list[str]:
"""
Scan HTTP `request` events for tool-identifying headers.
Checks User-Agent, X-Mailer, and other headers case-insensitively
against `_HEADER_TOOL_SIGNATURES`. Returns a deduplicated list of
matched tool names in detection order.
"""
found: list[str] = []
seen: set[str] = set()
for e in events:
if e.event_type != "request":
continue
raw_headers = e.fields.get("headers")
if not raw_headers:
continue
# headers may arrive as a JSON string, a Python-repr string (legacy),
# or a dict already (in-memory / test paths).
if isinstance(raw_headers, str):
try:
headers: dict[str, str] = json.loads(raw_headers)
except (json.JSONDecodeError, ValueError):
# Backward-compat: events written before the JSON-encode fix
# were serialized as Python repr via str(dict). ast.literal_eval
# handles that safely (no arbitrary code execution).
try:
import ast as _ast
_parsed = _ast.literal_eval(raw_headers)
if isinstance(_parsed, dict):
headers = _parsed
else:
continue
except Exception: # nosec B112 — skip unparseable header values
continue
elif isinstance(raw_headers, dict):
headers = raw_headers
else:
continue
# Normalise header keys to lowercase for matching.
lc_headers: dict[str, str] = {k.lower(): str(v) for k, v in headers.items()}
for sig in _HEADER_TOOL_SIGNATURES:
name = sig["name"]
if name in seen:
continue
value = lc_headers.get(sig["header"])
if value is None:
continue
pattern = sig["pattern"]
if pattern.startswith("^"):
if re.match(pattern, value, re.IGNORECASE):
found.append(name)
seen.add(name)
else:
if pattern.lower() in value.lower():
found.append(name)
seen.add(name)
return found
# ─── Phase sequencing ───────────────────────────────────────────────────────
@_traced("profiler.phase_sequence")
def phase_sequence(events: list[LogEvent]) -> dict[str, Any]:
"""
Derive recon→exfil phase transition info.
Returns:
recon_end_ts : ISO timestamp of last recon-class event (or None)
exfil_start_ts : ISO timestamp of first exfil-class event (or None)
exfil_latency_s : seconds between them (None if not both present)
large_payload_count: count of events whose *fields* report a payload
≥ 1 MiB (heuristic for bulk data transfer)
"""
recon_end = None
exfil_start = None
large_payload_count = 0
for e in sorted(events, key=lambda x: x.timestamp):
if e.event_type in _RECON_EVENT_TYPES:
recon_end = e.timestamp
elif e.event_type in _EXFIL_EVENT_TYPES and exfil_start is None:
exfil_start = e.timestamp
for fname in _PAYLOAD_SIZE_FIELDS:
raw = e.fields.get(fname)
if raw is None:
continue
try:
if int(raw) >= 1_048_576:
large_payload_count += 1
break
except (TypeError, ValueError):
continue
latency: float | None = None
if recon_end is not None and exfil_start is not None and exfil_start >= recon_end:
latency = round((exfil_start - recon_end).total_seconds(), 3)
return {
"recon_end_ts": recon_end.isoformat() if recon_end else None,
"exfil_start_ts": exfil_start.isoformat() if exfil_start else None,
"exfil_latency_s": latency,
"large_payload_count": large_payload_count,
}
# ─── Sniffer rollup (OS fingerprint + retransmits) ──────────────────────────
@_traced("profiler.sniffer_rollup")
def sniffer_rollup(events: list[LogEvent]) -> dict[str, Any]:
"""
Roll up sniffer-emitted `tcp_syn_fingerprint` and `tcp_flow_timing`
events into a per-attacker summary.
OS guess priority:
1. Modal p0f label from os_guess field (if not "unknown"/empty).
2. TTL-based coarse bucket (linux / windows / embedded) as fallback.
Hop distance: median of non-zero reported values only.
"""
os_guesses: list[str] = []
ttl_values: list[str] = []
hops: list[int] = []
tcp_fp: dict[str, Any] | None = None
retransmits = 0
for e in events:
if e.event_type == _SNIFFER_SYN_EVENT:
og = e.fields.get("os_guess")
if og and og != "unknown":
os_guesses.append(og)
# Collect raw TTL for fallback OS derivation.
ttl_raw = e.fields.get("ttl") or e.fields.get("initial_ttl")
if ttl_raw:
ttl_values.append(ttl_raw)
# Only include hop distances that are valid and non-zero.
hop_raw = e.fields.get("hop_distance")
if hop_raw:
try:
hop_val = int(hop_raw)
if hop_val > 0:
hops.append(hop_val)
except (TypeError, ValueError):
pass
# Keep the latest fingerprint snapshot.
tcp_fp = {
"window": _int_or_none(e.fields.get("window")),
"wscale": _int_or_none(e.fields.get("wscale")),
"mss": _int_or_none(e.fields.get("mss")),
"options_sig": e.fields.get("options_sig", ""),
"has_sack": e.fields.get("has_sack") == "true",
"has_timestamps": e.fields.get("has_timestamps") == "true",
}
elif e.event_type == _SNIFFER_FLOW_EVENT:
try:
retransmits += int(e.fields.get("retransmits", "0"))
except (TypeError, ValueError):
pass
elif e.event_type == _PROBER_TCPFP_EVENT:
# Active-probe result: prober sent SYN to attacker, got SYN-ACK back.
# Field names differ from the passive sniffer (different emitter).
ttl_raw = e.fields.get("ttl")
if ttl_raw:
ttl_values.append(ttl_raw)
# Derive hop distance from observed TTL vs canonical initial TTL.
os_hint = _os_from_ttl(ttl_raw)
if os_hint:
initial = _INITIAL_TTL.get(os_hint)
if initial:
try:
hop_val = initial - int(ttl_raw)
if hop_val > 0:
hops.append(hop_val)
except (TypeError, ValueError):
pass
# Prober uses window_size/window_scale/options_order instead of
# the sniffer's window/wscale/options_sig.
tcp_fp = {
"window": _int_or_none(e.fields.get("window_size")),
"wscale": _int_or_none(e.fields.get("window_scale")),
"mss": _int_or_none(e.fields.get("mss")),
"options_sig": e.fields.get("options_order", ""),
"has_sack": e.fields.get("sack_ok") == "1",
"has_timestamps": e.fields.get("timestamp") == "1",
}
# Mode for the OS bucket — most frequently observed label.
os_guess: str | None = None
if os_guesses:
os_guess = Counter(os_guesses).most_common(1)[0][0]
else:
# TTL-based fallback: use the most common observed TTL value.
if ttl_values:
modal_ttl = Counter(ttl_values).most_common(1)[0][0]
os_guess = _os_from_ttl(modal_ttl)
# Median hop distance (robust to the occasional weird TTL).
hop_distance: int | None = None
if hops:
hop_distance = int(statistics.median(hops))
return {
"os_guess": os_guess,
"hop_distance": hop_distance,
"tcp_fingerprint": tcp_fp or {},
"retransmit_count": retransmits,
}
def _int_or_none(v: Any) -> int | None:
if v is None or v == "":
return None
try:
return int(v)
except (TypeError, ValueError):
return None
# ─── Composite: build the full AttackerBehavior record ──────────────────────
@_traced("profiler.build_behavior_record")
def build_behavior_record(events: list[LogEvent]) -> dict[str, Any]:

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"""Coarse behavior classification for DECNET attacker profiles."""
from __future__ import annotations
from typing import Any
from decnet.telemetry import traced as _traced
@_traced("profiler.classify_behavior")
def classify_behavior(stats: dict[str, Any], services_count: int) -> str:
"""
Coarse behavior bucket:
beaconing | interactive | scanning | brute_force | slow_scan | mixed | unknown
Heuristics (evaluated in priority order):
* `scanning` — ≥ 3 services touched OR mean IAT < 2 s, ≥ 3 events
* `brute_force` — 1 service, n ≥ 8, mean IAT < 5 s, CV < 0.6
* `beaconing` — CV < 0.35, mean IAT ≥ 5 s, ≥ 4 events
* `slow_scan` — ≥ 2 services, mean IAT ≥ 10 s, ≥ 4 events
* `interactive` — mean IAT < 5 s AND CV ≥ 0.5, ≥ 6 events
* `mixed` — catch-all for sessions with enough data
* `unknown` — too few data points
"""
n = stats.get("event_count") or 0
mean = stats.get("mean_iat_s")
cv = stats.get("cv")
if n < 3 or mean is None:
return "unknown"
# Slow scan / low-and-slow: multiple services with long gaps.
# Must be checked before generic scanning so slow multi-service sessions
# don't get mis-bucketed as a fast sweep.
if services_count >= 2 and mean >= 10.0 and n >= 4:
return "slow_scan"
# Scanning: broad service sweep (multi-service) or very rapid single-service bursts.
if n >= 3 and (
(services_count >= 3 and mean < 10.0)
or (services_count >= 2 and mean < 2.0)
):
return "scanning"
# Brute force: hammering one service rapidly and repeatedly.
if services_count == 1 and n >= 8 and mean < 5.0 and cv is not None and cv < 0.6:
return "brute_force"
# Beaconing: regular cadence over multiple events.
if cv is not None and cv < 0.35 and mean >= 5.0 and n >= 4:
return "beaconing"
# Interactive: short but irregular bursts (human or tool with think time).
if cv is not None and cv >= 0.5 and mean < 5.0 and n >= 6:
return "interactive"
return "mixed"

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"""OS / TCP fingerprint rollup for DECNET attacker profiles.
Consumes sniffer-emitted `tcp_syn_fingerprint` / `tcp_flow_timing` events and
active prober `tcpfp_fingerprint` events; derives a per-attacker summary
(os_guess, hop_distance, tcp_fingerprint snapshot, retransmit_count).
"""
from __future__ import annotations
import statistics
from collections import Counter
from typing import Any
from decnet.correlation.parser import LogEvent
from decnet.telemetry import traced as _traced
# Sniffer-emitted packet events that feed into fingerprint rollup.
_SNIFFER_SYN_EVENT: str = "tcp_syn_fingerprint"
_SNIFFER_FLOW_EVENT: str = "tcp_flow_timing"
# Prober-emitted active-probe result (SYN-ACK fingerprint of attacker machine).
_PROBER_TCPFP_EVENT: str = "tcpfp_fingerprint"
# Canonical initial TTL for each coarse OS bucket. Used to derive hop
# distance when only the observed TTL is available (prober path).
_INITIAL_TTL: dict[str, int] = {
"linux": 64,
"windows": 128,
"embedded": 255,
}
def _os_from_ttl(ttl_str: str | None) -> str | None:
"""Derive a coarse OS guess from observed TTL when p0f has no match."""
if not ttl_str:
return None
try:
ttl = int(ttl_str)
except (TypeError, ValueError):
return None
if 55 <= ttl <= 70:
return "linux"
if 115 <= ttl <= 135:
return "windows"
if 235 <= ttl <= 255:
return "embedded"
return None
def _int_or_none(v: Any) -> int | None:
if v is None or v == "":
return None
try:
return int(v)
except (TypeError, ValueError):
return None
@_traced("profiler.sniffer_rollup")
def sniffer_rollup(events: list[LogEvent]) -> dict[str, Any]:
"""
Roll up sniffer-emitted `tcp_syn_fingerprint` and `tcp_flow_timing`
events into a per-attacker summary.
OS guess priority:
1. Modal p0f label from os_guess field (if not "unknown"/empty).
2. TTL-based coarse bucket (linux / windows / embedded) as fallback.
Hop distance: median of non-zero reported values only.
"""
os_guesses: list[str] = []
ttl_values: list[str] = []
hops: list[int] = []
tcp_fp: dict[str, Any] | None = None
retransmits = 0
for e in events:
if e.event_type == _SNIFFER_SYN_EVENT:
og = e.fields.get("os_guess")
if og and og != "unknown":
os_guesses.append(og)
# Collect raw TTL for fallback OS derivation.
ttl_raw = e.fields.get("ttl") or e.fields.get("initial_ttl")
if ttl_raw:
ttl_values.append(ttl_raw)
# Only include hop distances that are valid and non-zero.
hop_raw = e.fields.get("hop_distance")
if hop_raw:
try:
hop_val = int(hop_raw)
if hop_val > 0:
hops.append(hop_val)
except (TypeError, ValueError):
pass
# Keep the latest fingerprint snapshot.
tcp_fp = {
"window": _int_or_none(e.fields.get("window")),
"wscale": _int_or_none(e.fields.get("wscale")),
"mss": _int_or_none(e.fields.get("mss")),
"options_sig": e.fields.get("options_sig", ""),
"has_sack": e.fields.get("has_sack") == "true",
"has_timestamps": e.fields.get("has_timestamps") == "true",
}
elif e.event_type == _SNIFFER_FLOW_EVENT:
try:
retransmits += int(e.fields.get("retransmits", "0"))
except (TypeError, ValueError):
pass
elif e.event_type == _PROBER_TCPFP_EVENT:
# Active-probe result: prober sent SYN to attacker, got SYN-ACK back.
# Field names differ from the passive sniffer (different emitter).
ttl_raw = e.fields.get("ttl")
if ttl_raw:
ttl_values.append(ttl_raw)
# Derive hop distance from observed TTL vs canonical initial TTL.
os_hint = _os_from_ttl(ttl_raw)
if os_hint:
initial = _INITIAL_TTL.get(os_hint)
if initial:
try:
hop_val = initial - int(ttl_raw)
if hop_val > 0:
hops.append(hop_val)
except (TypeError, ValueError):
pass
# Prober uses window_size/window_scale/options_order instead of
# the sniffer's window/wscale/options_sig.
tcp_fp = {
"window": _int_or_none(e.fields.get("window_size")),
"wscale": _int_or_none(e.fields.get("window_scale")),
"mss": _int_or_none(e.fields.get("mss")),
"options_sig": e.fields.get("options_order", ""),
"has_sack": e.fields.get("sack_ok") == "1",
"has_timestamps": e.fields.get("timestamp") == "1",
}
# Mode for the OS bucket — most frequently observed label.
os_guess: str | None = None
if os_guesses:
os_guess = Counter(os_guesses).most_common(1)[0][0]
else:
# TTL-based fallback: use the most common observed TTL value.
if ttl_values:
modal_ttl = Counter(ttl_values).most_common(1)[0][0]
os_guess = _os_from_ttl(modal_ttl)
# Median hop distance (robust to the occasional weird TTL).
hop_distance: int | None = None
if hops:
hop_distance = int(statistics.median(hops))
return {
"os_guess": os_guess,
"hop_distance": hop_distance,
"tcp_fingerprint": tcp_fp or {},
"retransmit_count": retransmits,
}

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"""Recon → exfil phase sequencing for DECNET attacker profiles."""
from __future__ import annotations
from typing import Any
from decnet.correlation.parser import LogEvent
from decnet.telemetry import traced as _traced
# Events that signal "recon" phase (scans, probes, auth attempts).
_RECON_EVENT_TYPES: frozenset[str] = frozenset({
"scan", "connection", "banner", "probe",
"login_attempt", "auth", "auth_failure",
})
# Events that signal "exfil" / action-on-objective phase.
_EXFIL_EVENT_TYPES: frozenset[str] = frozenset({
"download", "upload", "file_transfer", "data_exfil",
"command", "exec", "query", "shell_input",
})
# Fields carrying payload byte counts (for "large payload" detection).
_PAYLOAD_SIZE_FIELDS: tuple[str, ...] = ("bytes", "size", "content_length")
@_traced("profiler.phase_sequence")
def phase_sequence(events: list[LogEvent]) -> dict[str, Any]:
"""
Derive recon→exfil phase transition info.
Returns:
recon_end_ts : ISO timestamp of last recon-class event (or None)
exfil_start_ts : ISO timestamp of first exfil-class event (or None)
exfil_latency_s : seconds between them (None if not both present)
large_payload_count: count of events whose *fields* report a payload
≥ 1 MiB (heuristic for bulk data transfer)
"""
recon_end = None
exfil_start = None
large_payload_count = 0
for e in sorted(events, key=lambda x: x.timestamp):
if e.event_type in _RECON_EVENT_TYPES:
recon_end = e.timestamp
elif e.event_type in _EXFIL_EVENT_TYPES and exfil_start is None:
exfil_start = e.timestamp
for fname in _PAYLOAD_SIZE_FIELDS:
raw = e.fields.get(fname)
if raw is None:
continue
try:
if int(raw) >= 1_048_576:
large_payload_count += 1
break
except (TypeError, ValueError):
continue
latency: float | None = None
if recon_end is not None and exfil_start is not None and exfil_start >= recon_end:
latency = round((exfil_start - recon_end).total_seconds(), 3)
return {
"recon_end_ts": recon_end.isoformat() if recon_end else None,
"exfil_start_ts": exfil_start.isoformat() if exfil_start else None,
"exfil_latency_s": latency,
"large_payload_count": large_payload_count,
}

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"""Inter-arrival timing statistics for DECNET attacker profiles."""
from __future__ import annotations
import statistics
from typing import Any
from decnet.correlation.parser import LogEvent
from decnet.telemetry import traced as _traced
@_traced("profiler.timing_stats")
def timing_stats(events: list[LogEvent]) -> dict[str, Any]:
"""
Compute inter-arrival-time statistics across *events* (sorted by ts).
Returns a dict with:
mean_iat_s, median_iat_s, stdev_iat_s, min_iat_s, max_iat_s, cv,
event_count, duration_s
For n < 2 events the interval-based fields are None/0.
"""
if not events:
return {
"event_count": 0,
"duration_s": 0.0,
"mean_iat_s": None,
"median_iat_s": None,
"stdev_iat_s": None,
"min_iat_s": None,
"max_iat_s": None,
"cv": None,
}
sorted_events = sorted(events, key=lambda e: e.timestamp)
duration_s = (sorted_events[-1].timestamp - sorted_events[0].timestamp).total_seconds()
if len(sorted_events) < 2:
return {
"event_count": len(sorted_events),
"duration_s": round(duration_s, 3),
"mean_iat_s": None,
"median_iat_s": None,
"stdev_iat_s": None,
"min_iat_s": None,
"max_iat_s": None,
"cv": None,
}
iats = [
(sorted_events[i].timestamp - sorted_events[i - 1].timestamp).total_seconds()
for i in range(1, len(sorted_events))
]
# Exclude spuriously-negative (clock-skew) intervals.
iats = [v for v in iats if v >= 0]
if not iats:
return {
"event_count": len(sorted_events),
"duration_s": round(duration_s, 3),
"mean_iat_s": None,
"median_iat_s": None,
"stdev_iat_s": None,
"min_iat_s": None,
"max_iat_s": None,
"cv": None,
}
mean = statistics.fmean(iats)
median = statistics.median(iats)
stdev = statistics.pstdev(iats) if len(iats) > 1 else 0.0
cv = (stdev / mean) if mean > 0 else None
return {
"event_count": len(sorted_events),
"duration_s": round(duration_s, 3),
"mean_iat_s": round(mean, 3),
"median_iat_s": round(median, 3),
"stdev_iat_s": round(stdev, 3),
"min_iat_s": round(min(iats), 3),
"max_iat_s": round(max(iats), 3),
"cv": round(cv, 4) if cv is not None else None,
}

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"""Tool attribution for DECNET attacker profiles.
Two detection paths:
* `guess_tools()` — matches beacon cadence (mean IAT + CV jitter) against
known C2 default profiles (Cobalt Strike, Sliver, Havoc, Mythic).
* `detect_tools_from_headers()` — scans HTTP `request` events for
tool-identifying User-Agent / X-Mailer / etc. headers (Nmap NSE, sqlmap,
nuclei, masscan, metasploit, curl, and friends).
"""
from __future__ import annotations
import json
import re
from typing import Any
from decnet.correlation.parser import LogEvent
from decnet.telemetry import traced as _traced
# ─── C2 tool attribution signatures (beacon timing) ─────────────────────────
#
# Each entry lists the default beacon cadence profile of a popular C2.
# A profile *matches* an attacker when:
# - mean inter-event time is within ±`interval_tolerance` seconds, AND
# - jitter (cv = stdev / mean) is within ±`jitter_tolerance`
#
# Multiple matches are all returned (attacker may run multiple implants).
_TOOL_SIGNATURES: tuple[dict[str, Any], ...] = (
{
"name": "cobalt_strike",
"interval_s": 60.0,
"interval_tolerance_s": 8.0,
"jitter_cv": 0.20,
"jitter_tolerance": 0.05,
},
{
"name": "sliver",
"interval_s": 60.0,
"interval_tolerance_s": 10.0,
"jitter_cv": 0.30,
"jitter_tolerance": 0.08,
},
{
"name": "havoc",
"interval_s": 45.0,
"interval_tolerance_s": 8.0,
"jitter_cv": 0.10,
"jitter_tolerance": 0.03,
},
{
"name": "mythic",
"interval_s": 30.0,
"interval_tolerance_s": 6.0,
"jitter_cv": 0.15,
"jitter_tolerance": 0.03,
},
)
# ─── Header-based tool signatures ───────────────────────────────────────────
#
# Scanned against HTTP `request` events. `pattern` is a case-insensitive
# substring (or a regex anchored with ^ if it starts with that character).
# `header` is matched case-insensitively against the event's headers dict.
_HEADER_TOOL_SIGNATURES: tuple[dict[str, str], ...] = (
{"name": "nmap", "header": "user-agent", "pattern": "Nmap Scripting Engine"},
{"name": "gophish", "header": "x-mailer", "pattern": "gophish"},
{"name": "nikto", "header": "user-agent", "pattern": "Nikto"},
{"name": "sqlmap", "header": "user-agent", "pattern": "sqlmap"},
{"name": "nuclei", "header": "user-agent", "pattern": "Nuclei"},
{"name": "masscan", "header": "user-agent", "pattern": "masscan"},
{"name": "zgrab", "header": "user-agent", "pattern": "zgrab"},
{"name": "metasploit", "header": "user-agent", "pattern": "Metasploit"},
{"name": "curl", "header": "user-agent", "pattern": "^curl/"},
{"name": "python_requests", "header": "user-agent", "pattern": "python-requests"},
{"name": "gobuster", "header": "user-agent", "pattern": "gobuster"},
{"name": "dirbuster", "header": "user-agent", "pattern": "DirBuster"},
{"name": "hydra", "header": "user-agent", "pattern": "hydra"},
{"name": "wfuzz", "header": "user-agent", "pattern": "Wfuzz"},
)
def guess_tools(mean_iat_s: float | None, cv: float | None) -> list[str]:
"""
Match (mean_iat, cv) against known C2 default beacon profiles.
Returns a list of all matching tool names (may be empty). Multiple
matches are all returned because an attacker can run several implants.
"""
if mean_iat_s is None or cv is None:
return []
hits: list[str] = []
for sig in _TOOL_SIGNATURES:
if abs(mean_iat_s - sig["interval_s"]) > sig["interval_tolerance_s"]:
continue
if abs(cv - sig["jitter_cv"]) > sig["jitter_tolerance"]:
continue
hits.append(sig["name"])
return hits
# Keep the old name as an alias so callers that expected a single string still
# compile, but mark it deprecated. Returns the first hit or None.
def guess_tool(mean_iat_s: float | None, cv: float | None) -> str | None:
"""Deprecated: use guess_tools() instead."""
hits = guess_tools(mean_iat_s, cv)
if len(hits) == 1:
return hits[0]
return None
@_traced("profiler.detect_tools_from_headers")
def detect_tools_from_headers(events: list[LogEvent]) -> list[str]:
"""
Scan HTTP `request` events for tool-identifying headers.
Checks User-Agent, X-Mailer, and other headers case-insensitively
against `_HEADER_TOOL_SIGNATURES`. Returns a deduplicated list of
matched tool names in detection order.
"""
found: list[str] = []
seen: set[str] = set()
for e in events:
if e.event_type != "request":
continue
raw_headers = e.fields.get("headers")
if not raw_headers:
continue
# headers may arrive as a JSON string, a Python-repr string (legacy),
# or a dict already (in-memory / test paths).
if isinstance(raw_headers, str):
try:
headers: dict[str, str] = json.loads(raw_headers)
except (json.JSONDecodeError, ValueError):
# Backward-compat: events written before the JSON-encode fix
# were serialized as Python repr via str(dict). ast.literal_eval
# handles that safely (no arbitrary code execution).
try:
import ast as _ast
_parsed = _ast.literal_eval(raw_headers)
if isinstance(_parsed, dict):
headers = _parsed
else:
continue
except Exception: # nosec B112 — skip unparseable header values
continue
elif isinstance(raw_headers, dict):
headers = raw_headers
else:
continue
# Normalise header keys to lowercase for matching.
lc_headers: dict[str, str] = {k.lower(): str(v) for k, v in headers.items()}
for sig in _HEADER_TOOL_SIGNATURES:
name = sig["name"]
if name in seen:
continue
value = lc_headers.get(sig["header"])
if value is None:
continue
pattern = sig["pattern"]
if pattern.startswith("^"):
if re.match(pattern, value, re.IGNORECASE):
found.append(name)
seen.add(name)
else:
if pattern.lower() in value.lower():
found.append(name)
seen.add(name)
return found