File size: 8,184 Bytes
955a66f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
from __future__ import annotations

from typing import Any

import numpy as np
import pandas as pd

from src.domain import (
    BURST_WINDOW_MINUTES,
    FEATURE_COLUMNS,
    SENSITIVE_TYPES,
    Split,
    TEST_START_ISO,
)
from src.mapper import normalize_event
from src.parsers import parse_timestamp
from src.ruleset import maintenance_match, severity_for


def events_frame(rows: list[dict[str, Any]] | pd.DataFrame) -> pd.DataFrame:
    if isinstance(rows, pd.DataFrame):
        records = rows.to_dict(orient="records")
    else:
        records = list(rows)
    cleaned = [normalize_event(row) for row in records]
    frame = pd.DataFrame(cleaned)
    if frame.empty:
        return frame
    frame["ts"] = [parse_timestamp(value) for value in frame["timestamp"]]
    valid = frame["ts"].notna() & frame["event_name"].astype(str).ne("")
    frame = frame.loc[valid].copy().reset_index(drop=True)
    if frame.empty:
        return frame
    test_start = pd.Timestamp(TEST_START_ISO)
    existing = frame["split"].replace("", Split.DEVELOPMENT.value)
    frame["split"] = np.where(pd.to_datetime(frame["ts"], utc=True) >= test_start, Split.TEST.value, existing)
    frame["hour"] = pd.to_datetime(frame["ts"], utc=True).dt.hour
    frame["weekday"] = pd.to_datetime(frame["ts"], utc=True).dt.weekday
    frame["weekend"] = frame["weekday"].isin([5, 6]).astype(float)
    human = frame["actor_kind"].eq("human")
    unusual = human & ((frame["hour"] < 6) | (frame["hour"] >= 22) | frame["weekday"].eq(6))
    frame["unusual_hour"] = unusual.astype(float)
    frame["in_window"] = frame["weekday"].eq(6) & frame["hour"].between(2, 5)
    flags = frame.apply(
        lambda row: {
            "cidr_open": bool(row.get("cidr_open")),
            "policy_public": bool(row.get("policy_public")),
            "admin_policy": bool(row.get("admin_policy")),
            "logging_off": bool(row.get("logging_off")),
            "detector_off": bool(row.get("detector_off")),
            "wildcard_trust": bool(row.get("wildcard_trust")),
            "is_root": row.get("actor_kind") == "root",
            "hardening": bool(row.get("hardening")),
        },
        axis=1,
    )
    frame["severity"] = [
        severity_for(str(row.change_type), flags.iloc[idx]).value for idx, row in enumerate(frame.itertuples(index=False))
    ]
    frame["in_maintenance"] = [
        maintenance_match(
            str(row.account_alias),
            str(row.actor_alias),
            str(row.change_type),
            flags.iloc[idx],
            str(row.change_ticket or ""),
            bool(row.in_window),
        )
        for idx, row in enumerate(frame.itertuples(index=False))
    ]
    frame["approval_status"] = np.where(frame["in_maintenance"], "approved_window", "none")
    frame["approval_status"] = np.where(
        frame["change_ticket"].astype(str).ne("") & ~frame["in_maintenance"],
        "unknown",
        frame["approval_status"],
    )
    frame = _pair_before_after(frame)
    frame = _burst_counts(frame)
    frame["is_root"] = frame["actor_kind"].eq("root").astype(float)
    frame["is_service"] = frame["actor_kind"].eq("service").astype(float)
    frame["is_human"] = frame["actor_kind"].eq("human").astype(float)
    frame["error_event"] = frame["error_code"].astype(str).ne("").astype(float)
    frame["sensitive"] = frame["change_type"].isin(SENSITIVE_TYPES) & ~frame["hardening"].astype(bool)
    return frame.sort_values(["ts", "event_id"]).reset_index(drop=True)


def _pair_before_after(frame: pd.DataFrame) -> pd.DataFrame:
    work = frame.sort_values("ts").copy()
    before_ids: list[str] = []
    before_known: list[bool] = []
    after_known: list[bool] = []
    for idx, row in work.iterrows():
        if row["change_type"] not in SENSITIVE_TYPES or row["hardening"]:
            before_ids.append("")
            before_known.append(False)
            after_known.append(False)
            continue
        prior = work.loc[
            (work["ts"] < row["ts"])
            & (work["account_alias"] == row["account_alias"])
            & (work["resource_alias"] == row["resource_alias"])
            & (work["resource_alias"].astype(str).ne("res_unknown"))
        ]
        if prior.empty:
            before_ids.append("")
            before_known.append(False)
            after_known.append(not bool(row.get("incomplete")))
            continue
        before_ids.append(str(prior.iloc[-1]["event_id"]))
        before_known.append(True)
        after_known.append(not bool(row.get("incomplete")))
    work["before_event_id"] = before_ids
    work["after_event_id"] = np.where(work["event_id"].astype(str).ne(""), work["event_id"], "")
    work["has_before"] = np.array(before_known, dtype=float)
    work["has_after"] = np.array(after_known, dtype=float)
    work["before_state"] = np.where(work["has_before"] >= 1, "known", "unknown")
    work["after_state"] = np.where(work["has_after"] >= 1, "known", "unknown")
    return work


def _burst_counts(frame: pd.DataFrame) -> pd.DataFrame:
    work = frame.sort_values("ts").copy()
    counts = []
    window = pd.Timedelta(minutes=BURST_WINDOW_MINUTES)
    sensitive = work["change_type"].isin(SENSITIVE_TYPES) & ~work["hardening"].astype(bool)
    for _, row in work.iterrows():
        if not bool(sensitive.loc[row.name] if row.name in sensitive.index else False):
            counts.append(0)
            continue
        mask = (
            (work["actor_alias"] == row["actor_alias"])
            & (work["ts"] <= row["ts"])
            & (work["ts"] >= row["ts"] - window)
            & sensitive
        )
        counts.append(int(mask.sum()))
    work["burst_count"] = counts
    return work


def feature_matrix(frame: pd.DataFrame) -> pd.DataFrame:
    if frame.empty:
        return pd.DataFrame(columns=list(FEATURE_COLUMNS))
    data = {}
    for column in FEATURE_COLUMNS:
        if column == "severity_weight":
            data[column] = frame["severity"].map({"high": 4.0, "medium": 3.2, "low": 1.8}).fillna(0.0)
        elif column in frame.columns:
            data[column] = pd.to_numeric(frame[column], errors="coerce").fillna(0.0)
        else:
            data[column] = 0.0
    return pd.DataFrame(data, index=frame.index)


def attach_gold(frame: pd.DataFrame, gold: pd.DataFrame | list[dict[str, Any]] | None) -> pd.DataFrame:
    out = frame.copy()
    out["gold_event_ids"] = ""
    out["gold_family"] = ""
    out["detect_delay_min"] = np.nan
    if gold is None:
        return out
    gold_frame = gold if isinstance(gold, pd.DataFrame) else pd.DataFrame(gold)
    if gold_frame.empty:
        return out
    gold_frame = gold_frame.copy()
    gold_frame["start_ts"] = [parse_timestamp(value) for value in gold_frame["start"]]
    gold_frame["end_ts"] = [parse_timestamp(value) for value in gold_frame["end"]]
    for event in gold_frame.itertuples(index=False):
        lab_id = str(event.event_id)
        direct = out["lab_event_id"].astype(str).eq(lab_id) | out["event_id"].astype(str).eq(lab_id)
        if event.start_ts and event.end_ts:
            overlap = (out["ts"] >= event.start_ts) & (out["ts"] <= event.end_ts)
            if getattr(event, "account_alias", ""):
                overlap = overlap & out["account_alias"].astype(str).eq(str(event.account_alias))
            if getattr(event, "actor_alias", ""):
                overlap = overlap & out["actor_alias"].astype(str).eq(str(event.actor_alias))
        else:
            overlap = pd.Series(False, index=out.index)
        hit = direct | overlap
        if not hit.any():
            continue
        current = out.loc[hit, "gold_event_ids"].astype(str)
        out.loc[hit, "gold_event_ids"] = np.where(current.eq("") | current.eq("nan"), lab_id, current + "," + lab_id)
        out.loc[hit, "gold_family"] = str(event.family)
        delay = (pd.to_datetime(out.loc[hit, "ts"], utc=True) - pd.Timestamp(event.start_ts)).dt.total_seconds() / 60.0
        out.loc[hit, "detect_delay_min"] = delay
    return out


def change_view(frame: pd.DataFrame) -> pd.DataFrame:
    if frame.empty:
        return frame
    return frame.loc[frame["change_type"].isin(SENSITIVE_TYPES)].copy()