File size: 6,635 Bytes
b8630cb
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import re
from sentence_transformers import SentenceTransformer
import numpy as np
from sklearn.metrics.pairwise import cosine_similarity
from urllib.parse import urlparse
from difflib import SequenceMatcher
import os
import pickle

class ExternalAnalysisAgent:
    def __init__(self):
        print("Loading External Analysis Agent...")
        self.model = SentenceTransformer('sentence-transformers/all-MiniLM-L6-v2')
        
        # Load pickle models for URL analysis
        model_dir = os.path.join(os.path.dirname(os.path.dirname(__file__)), 'models')
        try:
            with open(os.path.join(model_dir, 'phishing_new.pkl'), 'rb') as f:
                self.url_ml_model = pickle.load(f)
            with open(os.path.join(model_dir, 'vectorizerurl_new.pkl'), 'rb') as f:
                self.url_vectorizer = pickle.load(f)
            self.has_url_ml = True
            print("Successfully loaded URL ML models.")
        except Exception as e:
            print(f"Failed to load URL ML models: {e}")
            self.has_url_ml = False
        
        self.phishing_patterns = [
            "verify your account immediately",
            "suspicious activity detected",
            "click here to confirm",
            "your account will be suspended",
            "update your payment information",
            "unusual sign-in attempt",
            "secure your account now",
            "limited time offer",
            "you have won a prize",
            "inheritance money transfer"
        ]
        
        self.suspicious_tlds = ['.xyz', '.top', '.club', '.online', '.site', '.win', '.bid']
        
        self.legitimate_domains = ['google.com', 'microsoft.com', 'amazon.com', 'paypal.com', 'apple.com']
        
        self.pattern_embeddings = self.model.encode(self.phishing_patterns)
        print("External Analysis Agent loaded successfully!")
    
    def analyze_url_risk(self, url):
        """Analyze URL for suspicious patterns"""
        risk_score = 0.0
        reasons = []
        
        for tld in self.suspicious_tlds:
            if url.lower().endswith(tld) or tld in url.lower():
                risk_score += 0.3
                reasons.append(f"Suspicious TLD: {tld}")
                break
        
        if re.search(r'\d+\.\d+\.\d+\.\d+', url):
            risk_score += 0.4
            reasons.append("IP address used instead of domain name")
        
        if url.count('.') > 3:
            risk_score += 0.2
            reasons.append("Excessive subdomains")
        
        shortening_services = ['bit.ly', 'tinyurl', 'goo.gl', 'ow.ly', 'tiny.cc']
        for service in shortening_services:
            if service in url.lower():
                risk_score += 0.3
                reasons.append(f"URL shortening service detected: {service}")
                break
        
        suspicious_keywords = ['login', 'signin', 'verify', 'account', 'secure', 'update', 'confirm']
        for keyword in suspicious_keywords:
            if keyword in url.lower():
                risk_score += 0.1
                reasons.append(f"Suspicious keyword in URL: '{keyword}'")
                break
        
        domain_similarity = self.check_domain_similarity(url)
        if domain_similarity > 0.7:
            risk_score += 0.3
            reasons.append("Domain similar to legitimate brand")
            
        url_ml_prob = 0.0
        if self.has_url_ml:
            try:
                features = self.url_vectorizer.transform([url])
                # phishing.pkl is LogisticRegression
                url_ml_prob = self.url_ml_model.predict_proba(features)[0][1]
                
                # Hybrid Logic: Weight the ML model heavily if it has high confidence
                if url_ml_prob > 0.8:
                    risk_score = max(risk_score, 0.9)
                    reasons.append(f"ML model identified highly malicious URL structure (Score: {url_ml_prob:.1%})")
                elif url_ml_prob > 0.5:
                    risk_score = max(risk_score, 0.6)
                    reasons.append(f"ML model flagged suspicious URL structure (Score: {url_ml_prob:.1%})")
                
            except Exception as e:
                print(f"Error predicting URL with ML model: {e}")
        
        return min(risk_score, 1.0), reasons, url_ml_prob
    
    def check_domain_similarity(self, url):
        """Check if domain is similar to legitimate domains"""
        domain = self.extract_domain(url)
        max_similarity = 0.0
        
        for legit_domain in self.legitimate_domains:
            similarity = SequenceMatcher(None, domain.lower(), legit_domain).ratio()
            max_similarity = max(max_similarity, similarity)
        
        return max_similarity
    
    def extract_domain(self, url):
        """Extract domain from URL"""
        parsed = urlparse(url)
        domain = parsed.netloc or parsed.path.split('/')[0]
        return domain
    
    def analyze(self, input_data):
        """Main analysis function"""
        text = input_data['cleaned_text']
        urls = input_data['urls']
        
        results = {
            'url_risk': 0.0,
            'url_ml_risk': 0.0,
            'domain_similarity': 0.0,
            'suspicious_patterns': [],
            'risk_factors': [],
            'overall_risk': 0.0
        }
        
        if urls:
            url_risks = []
            url_ml_risks = []
            for url in urls:
                risk, reasons, ml_prob = self.analyze_url_risk(url)
                url_risks.append(risk)
                url_ml_risks.append(ml_prob)
                results['risk_factors'].extend(reasons)
            
            results['url_risk'] = np.mean(url_risks) if url_risks else 0
            results['url_ml_risk'] = max(url_ml_risks) if url_ml_risks else 0
            
            results['domain_similarity'] = self.check_domain_similarity(urls[0])
        
        try:
            text_embedding = self.model.encode([text])
            similarities = cosine_similarity(text_embedding, self.pattern_embeddings)[0]
            
            if max(similarities) > 0.6:
                results['suspicious_patterns'].append("Text similar to known phishing patterns")
                results['overall_risk'] += 0.3
        except Exception as e:
            print(f"Error in semantic similarity: {e}")
        
        results['overall_risk'] = min(
            results['url_risk'] * 0.6 + 
            results['domain_similarity'] * 0.4 +
            len(results['suspicious_patterns']) * 0.1,
            1.0
        )
        
        return results