🎯 How Cybercriminals Exploit CSS to Bypass Email Security & Track Users

Cybercriminals have found a sneaky new trick: abusing CSS (Cascading Style Sheets) to slip past email filters and spy on users' behavior! 🔥

🚨 What’s the Attack?

1️⃣ Spam Filter Evasion

Attackers hide random junk text using CSS properties like:

• text-indent

• opacity: 0

• display: none

These invisible elements confuse security filters, letting phishing emails sneak through undetected! 🎭

2️⃣ User Tracking & Fingerprinting

Using CSS @media queries, attackers gather:

📱 Screen size
🌙 Color preferences
🌐 Language settings
🖨️ Whether you printed or opened the email

All this info = perfect for targeted attacks! 🎯

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🧂 Hidden Text Salting: What’s That?

Cybercriminals sprinkle random comments & invisible text inside emails (salting), making it harder for filters to recognize dangerous patterns. Combined with CSS, it becomes a powerful evasion technique! 🧩

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💥 Why It’s Dangerous

⚠️ Phishing: Hidden CSS tricks redirect you to fake sites.
🔍 Privacy Invasion: Attackers fingerprint you silently.

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🛡️ How to Stay Safe

✅ Advanced Filters: Choose email security tools that detect CSS-based obfuscation.
✅ Disable Remote Content: Block external CSS/images by default.
✅ Use Privacy Proxies: Strip tracking elements before emails load.
✅ Harden Email Clients: Restrict external resource rendering.

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🔑 Conclusion

This creative misuse of CSS shows how attackers adapt fast. Organizations & users need to up their game — not just blocking scripts, but recognizing how even passive tools like CSS can be weaponized! 🕵️‍♂️⚔️