File size: 4,788 Bytes
2cc7f91
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
"""

Shared Feature Engineering for HTML-based Phishing Detection



Creates derived features from raw HTML features to improve model performance.

Used by both XGBoost and Random Forest training pipelines.

"""
import numpy as np
import pandas as pd
import logging

logger = logging.getLogger(__name__)


def engineer_features(X: pd.DataFrame) -> pd.DataFrame:
    """

    Create engineered features from raw HTML features.



    Adds ratio features, interaction terms and risk scores

    that capture phishing-specific patterns.



    Args:

        X: DataFrame with raw feature columns (no 'label'/'filename')



    Returns:

        DataFrame with original + engineered features (inf replaced by 0)

    """
    X = X.copy()

    # ---- Ratio features (division guarded by +1) ----
    X['forms_to_inputs_ratio'] = X['num_forms'] / (X['num_input_fields'] + 1)
    X['external_to_total_links'] = X['num_external_links'] / (X['num_links'] + 1)
    X['scripts_to_tags_ratio'] = X['num_scripts'] / (X['num_tags'] + 1)
    X['hidden_to_visible_inputs'] = X['num_hidden_fields'] / (X['num_input_fields'] + 1)
    X['password_to_inputs_ratio'] = X['num_password_fields'] / (X['num_input_fields'] + 1)
    X['empty_to_total_links'] = X['num_empty_links'] / (X['num_links'] + 1)
    X['images_to_tags_ratio'] = X['num_images'] / (X['num_tags'] + 1)
    X['iframes_to_tags_ratio'] = X['num_iframes'] / (X['num_tags'] + 1)

    # ---- Interaction features (suspicious combinations) ----
    X['forms_with_passwords'] = X['num_forms'] * X['num_password_fields']
    X['external_scripts_links'] = X['num_external_links'] * X['num_external_scripts']
    X['urgency_with_forms'] = X['num_urgency_keywords'] * X['num_forms']
    X['brand_with_forms'] = X['num_brand_mentions'] * X['num_forms']
    X['iframes_with_scripts'] = X['num_iframes'] * X['num_scripts']
    X['hidden_with_external'] = X['num_hidden_fields'] * X['num_external_form_actions']

    # ---- Content density features ----
    X['content_density'] = (X['text_length'] + 1) / (X['num_divs'] + X['num_spans'] + 1)
    X['form_density'] = X['num_forms'] / (X['num_divs'] + 1)
    X['scripts_per_form'] = X['num_scripts'] / (X['num_forms'] + 1)
    X['links_per_word'] = X['num_links'] / (X['num_words'] + 1)

    # ---- Risk scores ----
    X['phishing_risk_score'] = (
        X['num_urgency_keywords'] * 2 +
        X['num_brand_mentions'] * 2 +
        X['num_password_fields'] * 3 +
        X['num_iframes'] * 2 +
        X.get('num_hidden_iframes', 0) * 4 +
        X.get('num_anchor_text_mismatch', 0) * 3 +
        X.get('num_suspicious_tld_links', 0) * 2 +
        X.get('has_login_form', 0) * 3
    )

    X['form_risk_score'] = (
        X['num_password_fields'] * 3 +
        X['num_external_form_actions'] * 2 +
        X['num_empty_form_actions'] +
        X['num_hidden_fields']
    )

    X['obfuscation_score'] = (
        X['has_eval'] +
        X['has_unescape'] +
        X['has_escape'] +
        X['has_document_write'] +
        X.get('has_base64', 0) +
        X.get('has_atob', 0) +
        X.get('has_fromcharcode', 0)
    )

    X['legitimacy_score'] = (
        X['has_title'] +
        X.get('has_description', 0) +
        X.get('has_viewport', 0) +
        X.get('has_favicon', 0) +
        X.get('has_copyright', 0) +
        X.get('has_author', 0) +
        (X['num_meta_tags'] > 3).astype(int) +
        (X['num_css_files'] > 0).astype(int)
    )

    # ---- Boolean aggregations ----
    X['has_suspicious_elements'] = (
        (X.get('has_meta_refresh', 0) == 1) |
        (X['num_iframes'] > 0) |
        (X['num_hidden_fields'] > 3) |
        (X.get('has_location_replace', 0) == 1)
    ).astype(int)

    # ---- Clean up ----
    X = X.replace([np.inf, -np.inf], 0)
    X = X.fillna(0)

    return X


def get_engineered_feature_names() -> list[str]:
    """Return names of features added by engineer_features()."""
    return [
        # Ratios (8)
        'forms_to_inputs_ratio', 'external_to_total_links',
        'scripts_to_tags_ratio', 'hidden_to_visible_inputs',
        'password_to_inputs_ratio', 'empty_to_total_links',
        'images_to_tags_ratio', 'iframes_to_tags_ratio',
        # Interactions (6)
        'forms_with_passwords', 'external_scripts_links',
        'urgency_with_forms', 'brand_with_forms',
        'iframes_with_scripts', 'hidden_with_external',
        # Content density (4)
        'content_density', 'form_density', 'scripts_per_form', 'links_per_word',
        # Risk scores (4)
        'phishing_risk_score', 'form_risk_score',
        'obfuscation_score', 'legitimacy_score',
        # Boolean (1)
        'has_suspicious_elements',
    ]