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Manifest V3 · 100% on-device · No telemetry

Stop phishing before your password leaves the page.

PhishGuard is two things in one: a privacy-first browser extension that intercepts credential theft in real time, and a free, interactive platform to learn how phishing works and how to defend against it.

Install the extension Start learning →
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⚠️ PhishGuard blocked this submission — High Risk

You are on accounts-secure.example, but this form was about to send your information to collect.evil-harvest.tk. Nothing has been sent yet.

  • ● This form sends your data to a different site than the one you're viewing.
  • ● The domain "paypaI.com" imitates PayPal using a lookalike character.
  • ● The domain was registered only 3 days ago.
🔒

On-device analysis

Your content never leaves your machine

🚫

No telemetry

Zero tracking, zero analytics by default

🧩

Manifest V3

Chrome & Edge, with Firefox notes

📖

Open source

Auditable TypeScript, minimal permissions

🎯 Your learning path

Tick each module as you go — your progress is saved locally in your browser.

0/5

The Learning Platform · Module 1

What is phishing, really?

Phishing is a social-engineering attack where a criminal impersonates a trusted person, brand, or service to trick you into revealing secrets — passwords, card numbers, one-time codes, recovery phrases — or into installing malware. The message looks legitimate; the destination is not.

Phishing works on people, not just computers. It exploits trust, urgency, fear, and habit. That's why awareness — knowing the patterns below — is your strongest single defence, and why PhishGuard pairs a technical shield with this learning platform.

🎭

Impersonation

A cloned login page or spoofed sender pretends to be your bank, employer, or a service you use. The logo is free to copy; the domain is the part that can't be faked.

⏰

Urgency & fear

"Your account will be suspended in 24 hours." Pressure short-circuits careful thinking and pushes you to act before you verify.

🪝

The hook

A link or attachment leads to a credential-harvesting page or malware. One click and one form submission is all it takes.

Module 2

Know your enemy: types of phishing

Phishing has many delivery channels and targeting strategies. Recognising the category helps you spot the play.

Module 3

Anatomy of a phishing attempt

These are the exact signals PhishGuard scores automatically — learn to see them yourself, then try the interactive email below.

The red flags checklist

🔍 Dissect a real phishing email

Click the highlighted parts to reveal what's wrong. 0 / 5 found

From:
Subject:
To: undisclosed-recipients

We detected unusual activity on your account.

Please confirm your details here:

PayPal Security Team

Interactive · runs entirely in your browser

Try the URL Inspector

Paste any link and see the same heuristic checks PhishGuard's engine runs — homoglyphs, typosquats, IP hosts, the "@" trick, shorteners and more. Nothing is sent anywhere; the analysis happens locally in JavaScript.

⚠️ This demo is a teaching tool with a simplified ruleset. The real extension adds threat-intelligence feeds, content analysis, form-destination checks and a tamper-evident audit log.

Test yourself

Spot-the-Phish quiz

Five quick scenarios. Pick the safest action — then learn why.

Module 4

Best practices to prevent phishing

Habits that defeat the vast majority of attacks — with or without a tool.

🆘 If you think you've been phished

  1. Change the password immediately — from a device you trust, by typing the real address yourself.
  2. Enable or reset multi-factor authentication on that account.
  3. Check for unauthorised activity, rules, or forwarding you didn't create.
  4. If you reused that password anywhere, change it there too.
  5. Report it: to your IT/security team, the impersonated brand, and anti-phishing bodies (APWG, your national CERT).
  6. Watch for follow-up scams — once breached, you become a target.

Module 5 · The Extension

What PhishGuard does for you

Detection, protection, and a clear record — all on-device, explained in plain language at the moment of risk.

How it works

01

Inspect

Content scripts read the page URL, forms, and (in webmail) the open message — entirely locally.

02

Score

A weighted engine combines URL, content, form-destination and threat-intel signals into one of four verdicts.

03

Intervene

Risky form submissions are paused before the request fires; a modal shows exactly where your data was headed.

04

Record

Every event is appended to a hash-chained, tamper-evident audit log you can search and export — never uploaded.

Get started

Install & use PhishGuard

1 · Build & load (developer mode)

Clone the repo and produce the loadable dist/ folder:

git clone https://github.com/AshenWijesingha/PhishGuard
cd PhishGuard
npm install
npm run build      # outputs dist/
  1. Open chrome://extensions (or edge://extensions).
  2. Enable Developer mode.
  3. Click Load unpacked and choose the dist/ folder.
  4. Pin the 🛡️ icon — the badge shows each page's verdict.

2 · Configure & explore

  • •Dashboard → Settings: tune sensitivity thresholds, enable optional threat feeds (Safe Browsing, PhishTank, OpenPhish, URLhaus, or your enterprise feed), and toggle privacy mode.
  • •Allow / Block lists: mark false positives as trusted or block sites outright — a domain can only be on one list.
  • •Audit log & charts: review activity, verify the hash chain, and export to CSV/JSON.
  • •Learn tab: the same just-in-time education cards you see when a submission is blocked.

Firefox?

See BROWSER_COMPAT.md for the manifest deltas (event page, browser_specific_settings, declarativeNetRequest limits).

Glossary

The vocabulary of phishing defence, in one place.