If you have been following crypto news recently, you may have heard about the DNS hijacking attacks that targeted Velodrome and Aerodrome, two popular decentralized exchanges. Users lost approximately $700,000 to phishing pages that looked identical to the real websites. With Bitcoin trading near $39,500 and the DeFi ecosystem growing rapidly, understanding how to protect yourself from frontend attacks is no longer optional — it is essential. This guide walks you through everything you need to know, step by step.
The Basics
When you use a decentralized finance protocol like Uniswap, Aave, or Velodrome, you typically visit a website that provides a user-friendly interface for interacting with smart contracts on the blockchain. The website is the frontend — a visual layer that translates your clicks and inputs into blockchain transactions. The smart contracts themselves live on the blockchain and are immutable, meaning they cannot be changed once deployed.
A frontend attack happens when criminals manage to redirect a legitimate website address to a fake version that they control. This is typically done by compromising the domain name system, or DNS, which acts like the internet phone book. When you type in a website address, DNS tells your browser where to find it. If an attacker changes the DNS records, your browser will take you to the attacker server instead of the real one.
The fake website looks exactly like the real one. It has the same layout, the same colors, and the same buttons. But when you connect your wallet and approve a transaction, you are actually giving the attacker permission to take your tokens. This is exactly what happened with Velodrome and Aerodrome, where attackers compromised an insider at the domain registrar to redirect users to phishing pages.
Why It Matters
Frontend attacks are particularly dangerous because they bypass all the smart contract security that DeFi protocols invest heavily in. A protocol can have its code audited multiple times by top security firms, have a bug bounty program, and run on a battle-tested blockchain — but if the website you use to access it is compromised, none of that matters. You are still signing a malicious transaction.
These attacks are also becoming more common. As the total value locked in DeFi protocols grows and cryptocurrency prices rise, the financial incentives for attackers increase proportionally. The attack on Velodrome and Aerodrome was contained within four hours thanks to rapid response from security partners, but that was enough time for hundreds of thousands of dollars in losses.
Understanding this threat is the first step to protecting yourself. The good news is that with a few simple habits, you can dramatically reduce your risk of falling victim to a frontend attack.
Getting Started Guide
The most important habit you can develop is bookmarking the correct URLs for every DeFi protocol you use. Navigate to the protocol website through a verified official link — from their official Twitter account, Discord server, or documentation — and save it as a bookmark. Always access the protocol through your bookmark rather than typing the URL or searching for it. Search engines can display malicious ads that look like official results.
Before connecting your wallet, check the URL in your browser address bar carefully. Look for subtle misspellings, extra characters, or unusual domain extensions. The real Velodrome website uses a specific domain, and attackers sometimes register domains that differ by just one letter. If anything looks different from your bookmark, do not connect your wallet.
Use a hardware wallet for all significant DeFi interactions. Devices like Trezor and Keystone display the exact details of every transaction on their built-in screen before you approve it. Even if you are on a phishing website, the hardware wallet will show you what the transaction actually does — and you can reject it if something looks wrong. Software wallets like MetaMask provide some protection, but they rely on your computer screen, which the phishing website controls.
Install a transaction simulation browser extension. Tools like PocketUniverse and Wallet Guard analyze every transaction before you sign it and show you what will happen in plain language. They can detect when a seemingly normal transaction would actually drain your wallet, even if the website you are on is compromised.
Keep your token approvals minimal. When you interact with a DeFi protocol, you usually need to approve the protocol to spend your tokens. Many phishing attacks rely on getting you to approve unlimited spending. After completing a transaction, use a tool like Revoke.cash to revoke any unnecessary approvals. Make this a weekly habit.
Common Pitfalls
The biggest mistake new DeFi users make is trusting URLs that arrive through unsolicited messages. If someone sends you a link to a DeFi protocol through Telegram, Discord, or email — even if it looks official — do not click it. Always navigate through your verified bookmarks instead.
Another common error is approving unlimited token allowances when only a specific amount is needed. Most DeFi interfaces offer the option to approve only the exact amount required for your transaction. Use this option whenever available. Unlimited approvals are convenient but create a permanent vulnerability if the protocol or its frontend is ever compromised.
Users also frequently fail to verify transactions on their hardware wallet screen. The convenience of clicking approve without reading the details is tempting, but the entire purpose of a hardware wallet is to provide a trusted display that the compromised website cannot manipulate. Always read the transaction details on your device before confirming.
Next Steps
Once you have established these basic security habits, consider exploring decentralized alternatives to traditional website access. ENS domains ending in .eth can point to decentralized hosting on IPFS, which is resistant to the DNS hijacking attacks that plague traditional domains. Many DeFi protocols now maintain .eth addresses as backup access points. For maximum security, advanced users can interact with smart contracts directly through block explorers like Etherscan, completely bypassing frontend websites. While this requires more technical knowledge, it eliminates the frontend attack surface entirely. Start with the basics, build your habits, and gradually explore these more advanced options as you become more comfortable navigating the DeFi landscape.
Disclaimer: This article is for informational purposes only and does not constitute financial or investment advice. Always conduct your own research before making any financial decisions.
bookmark https://revoke.cash and check your approvals weekly. most people have dozens of stale unlimited approvals they forgot about
bookmarks dont help if the DNS is compromised. the fake site resolves to the real URL. you need to verify the contract address directly on etherscan, not trust the frontend
the Velodrome attack was classic DNS hijacking through a compromised registrar account. 2FA on your domain registrar is more important than 2FA on your exchange at this point
Bookmarking legitimate DeFi URLs and never clicking links from Discord or Telegram would prevent 90% of these attacks. People are just lazy about basic OpSec.
this comment should be pinned everywhere. your bookmark means nothing if DNS is hijacked. always verify the contract address on etherscan before signing anything
priya d is spot on. clicking links from discord and telegram is how 90% of people get wrecked. basic opsec beats fancy tools
this should be pinned on every defi discord. the number of people i see getting phished because they dont understand dns is depressing
the velodrome attack was textbook DNS hijack. fake site, real contracts, user signs a malicious approval thinking they are swapping. takes 2 seconds to lose everything
the hardware wallet verification section is exactly what newcomers need. took me 6 months of using defi before i learned about simulating transactions before signing
simulating transactions before signing should be taught in every crypto onboarding flow. tenderly and pocket universe save people thousands
hardware wallet plus etherscan contract verification prevents basically every phishing attack. doing defi with a hot wallet is playing roulette with your savings
DNS hijacking is way underrated as an attack vector. people obsess over smart contract audits while the frontend is trivially redirectable
helena is right that frontend security is the weak link. people spend hours researching smart contract audits then type their seed phrase into a fake site because the URL looked right