Download Work - 840 -2024- Bengla -www.mazabd.click... Access
def extract_features(subject: str) -> dict: # ---- Basic tokenisation ------------------------------------------------- tokens = re.split(r'\s+', subject.strip()) n_tokens = len(tokens) n_chars = len(subject)
# ---- Textual cues ------------------------------------------------------- upper_ratio = sum(c.isupper() for c in subject) / max(n_chars, 1) digit_ratio = sum(c.isdigit() for c in subject) / max(n_chars, 1) avg_token_len = np.mean([len(t) for t in tokens]) if tokens else 0 has_action = any(v in subject.lower() for v in "download","click","open","update","verify") has_suspicious = any(v in subject.lower() for v in suspicious_word_list) stop_ratio = sum(t.lower() in stop_words for t in tokens) / max(n_tokens, 1) hyphen_cnt = subject.count('-') ellipsis = subject.endswith('...') numeric_pattern = bool(re.search(r'\b\d3,\s*-\s*\d4\b', subject)) Download WORK - 840 -2024- Bengla -www.mazabd.click...
# Example simple risk score (0‑10) risk = 0 risk += int(upper_ratio > 0.4) * 1 risk += int(digit_ratio > 0.2) * 1 risk += int(has_action_verb) * 1 risk += int(has_suspicious_keyword) * 1 risk += int(domain_age_days < 30) * 2 risk += int(tld not in 'com','org','net','gov','edu') * 1 risk += int(num_hyphens > 2) * 1 risk += int(url_entropy > 4.0) * 1 risk = min(risk, 10) A more sophisticated approach is to feed all raw features into a (XGBoost, LightGBM) which automatically learns interaction effects (e.g., “high digit ratio and unknown TLD”). 5. Practical Implementation Checklist | Step | Action | Tool / Library | |------|--------|----------------| |1| Collect a labeled corpus (spam vs. legitimate subjects).| CSV / Parquet | |2| Parse each subject for the features above.| re , tldextract , email , nltk , sklearn | |3| Enrich URLs via external APIs (whois, VirusTotal, Google Safe Browsing).| python-whois , requests | |4| Vectorise text (TF‑IDF, word‑embeddings) for deeper semantic signals.| sklearn , gensim , sentence‑transformers | |5| Scale numeric columns (StandardScaler or MinMax) if using linear models.| sklearn.preprocessing | |6| Train & evaluate (cross‑validation, ROC‑AUC, PR‑AUC).| sklearn.model_selection | |7| Deploy as a micro‑service (FastAPI/Flask) that receives a subject line, returns a risk score + optional explanations (e.g., “high digit ratio, unknown TLD”).| FastAPI, Docker | |8| Monitor drift – keep an eye on feature distributions (e.g., sudden rise in new TLDs).| Prometheus + Grafana | 6. Example Code Snippet (End‑to‑End) import re, tldextract, datetime, numpy as np from collections import Counter from sklearn.feature_extraction.text import TfidfVectorizer def extract_features(subject: str) -> dict: # ---- Basic
"Download WORK - 840 -2024- Bengla -www.mazabd.click..." into an that can be fed to a spam‑/phishing‑detection model (e.g., a classic‑ML classifier, a gradient‑boosted tree, or a shallow neural net). The ideas are grouped by what the feature describes , why it matters, and how to compute it in a reproducible way (Python‑friendly pseudo‑code is included). 1. Text‑Based Features (what the subject says ) | # | Feature | Why it matters | Simple extraction (Python) | |---|---------|----------------|-----------------------------| | 1 | Token Count | Very short or very long subjects are atypical for legitimate business mail. | len(subject.split()) | | 2 | Character Count | Spam often packs many characters to hide keywords. | len(subject) | | 3 | Average Token Length | Long words → possible obfuscation. | np.mean([len(t) for t in subject.split()]) | | 4 | Upper‑case Ratio | Excessive caps = “shouting”, common in phishing. | sum(1 for c in subject if c.isupper()) / len(subject) | | 5 | Digit Ratio | High proportion of numbers (e.g., “840‑2024”) is a red flag. | sum(c.isdigit() for c in subject) / len(subject) | | 6 | Presence of Action Verbs (download, click, open, update…) | Direct calls‑to‑action are hallmark of malicious prompts. | any(v in subject.lower() for v in "download","click","open","update","verify") | | 7 | Suspicious Keywords (work, urgent, invoice, account, password…) | Common lure words. | any(k in subject.lower() for k in suspicious_word_list) | | 8 | Stop‑Word Ratio | Spam often reduces natural language flow → low stop‑word density. | stop_words = set(nltk.corpus.stopwords.words('english')) stop_ratio = sum(1 for t in tokens if t.lower() in stop_words) / len(tokens) | | 9 | N‑gram TF‑IDF Scores (bi‑grams, tri‑grams) | Captures patterns like “download work”, “840‑2024”. | Use sklearn.feature_extraction.text.TfidfVectorizer(ngram_range=(2,3)) on a corpus of subjects. | |10| Language Detection | “Bengla” hints at a language mismatch (English subject + foreign term). | langdetect.detect(subject) – flag if not the primary language of the organization. | |11| Spell‑Check Ratio | Misspellings (“Bengla” vs “Bangla”) are common in malicious mail. | spellchecker.unknown(tokens) → proportion. | |12| Entropy of Characters | High entropy can indicate random strings or encoded data. | entropy = -sum(p*np.log2(p) for p in np.bincount(list(subject.encode()))/len(subject)) | 2. URL‑Centric Features (what the subject exposes ) Even though the URL lives after the dash, the presence and shape of a domain in the subject is a strong signal. legitimate subjects)
# Dummy placeholders for reputation / age (replace with real API calls) domain_age_days = 9999 # e.g., today - creation_date domain_risk = 0 # 0 = clean, 1 = flagged