If you hold cryptocurrency, the September 19, 2023 attack on Balancer should be your wake-up call. Hackers stole $238,000 by hijacking the protocol’s actual website — not through a smart contract flaw, but by compromising the DNS records that direct your browser to the right server. Users who visited what looked like the legitimate balancer.fi site were tricked into approving malicious transactions that emptied their wallets. This guide explains exactly how these attacks work and what you can do to stay safe.
The Basics
A DNS hijacking attack works by redirecting the domain name you type into your browser — like balancer.fi — to a server controlled by attackers instead of the legitimate protocol. When you visit the compromised site, everything looks normal: the interface, the branding, the wallet connection prompt. But behind the scenes, the site has been modified to present you with malicious smart contract approvals instead of legitimate ones.
In the Balancer attack, users were prompted to switch to the blockchain network where they held the most funds, then asked to approve a transaction. The moment they confirmed, the malicious contract drained their tokens. On-chain investigator ZachXBT traced approximately $238,000 in stolen funds to a single attacker wallet address. The attacker quickly moved the funds across multiple chains and through exchanges, making recovery nearly impossible.
This type of attack is particularly dangerous because it exploits the trust users place in familiar website addresses. You would naturally be suspicious of a random link sent by a stranger, but when the same URL you have used dozens of times suddenly serves malicious content, your guard is down.
Why It Matters
DNS attacks are not theoretical threats — they happen regularly in the crypto space, and the losses are real. The Balancer attack followed a previous $900,000 exploit from just weeks earlier involving a different vulnerability in the same protocol. During the same week, claimants in the Celsius bankruptcy proceedings were targeted by phishing attacks. The pattern is clear: attackers target the crypto community with increasing sophistication and persistence.
With Bitcoin trading at $27,211 and Ethereum at $1,643 in September 2023, even a small percentage of your holdings represents significant value worth protecting. The cost of implementing basic security measures is minimal compared to the devastating impact of losing your entire portfolio to a single deceptive transaction.
Getting Started Guide
Follow these steps to significantly reduce your risk of falling victim to frontend attacks:
Step 1: Use a hardware wallet. Devices like Ledger or Trezor require physical button confirmation for every transaction. Even if a hacker compromises your computer and the website you are visiting, they cannot authorize a transaction without you pressing the physical buttons on your hardware wallet. This single investment provides protection against the majority of frontend attacks.
Step 2: Bookmark your DeFi sites. Instead of typing URLs or clicking links from search results, social media, or chat messages, save verified URLs as browser bookmarks. Navigate only through your bookmarks when accessing DeFi protocols. This eliminates the risk of visiting a misspelled or compromised domain through external links.
Step 3: Minimize token approvals. When interacting with DeFi protocols, approve only the specific amount of tokens you intend to use in a transaction rather than granting unlimited approval. After completing your transaction, revoke the approval using tools like Revoke.cash or Etherscan’s token approval checker.
Step 4: Verify through multiple channels. Before connecting your wallet to any DeFi site, check the protocol’s official Twitter account and Discord server for the confirmed URL. If there is an active security incident, these channels will have the latest information. Never trust a URL shared in Telegram groups or Discord DMs during a crisis.
Step 5: Use security browser extensions. Tools like Joinfire can detect malicious contract interactions before you sign them, providing a real-time safety net that warns you when something looks suspicious about the transaction you are about to approve.
Common Pitfalls
The most dangerous mistake is assuming that a familiar URL is always safe. The entire point of DNS hijacking is to make a malicious site accessible through a legitimate address. Another common error is granting unlimited token approvals for convenience — this gives the protocol (or a compromised version of it) the ability to drain your entire balance of that token at any time. Finally, many users skip the step of checking official channels before connecting their wallets, especially during market volatility when they feel pressure to act quickly.
Attackers deliberately exploit urgency. The Balancer attackers struck while users were already on edge from the previous month’s $900,000 exploit, creating a climate where fear and confusion made people more likely to make hasty decisions.
Next Steps
Start by auditing your current wallet approvals today. Visit Revoke.cash and connect each of your wallets to see which contracts have spending permissions. Revoke any approvals you do not actively need. Then, set up a dedicated browser profile for your DeFi activities, install a security extension, and bookmark all the protocols you use regularly. If you do not already own a hardware wallet, make that your next purchase — it is the single most impactful security upgrade you can make for your cryptocurrency holdings. The crypto ecosystem rewards those who take security seriously and punishes those who do not. Make sure you are in the first group.
Disclaimer: This article is for informational purposes only and does not constitute financial or investment advice. Always conduct your own research before making investment decisions.
the balancer attack was 238k from changing a single DNS record. social engineering the registrar is usually easier than cracking the smart contract
Bora K. exactly this. social engineering the DNS registrar is like a $500 exploit that returns 200k+. worst ROI ratio in all of crypto
Bora K. single DNS record change for 238k shows why social engineering registrars is worst ROI ratio in crypto
DNS_warrior 238k from changing one DNS record is insane ROI. social engineering the registrar is way easier than cracking smart contracts and pays better
Balancer lost $238k to a DNS record change. one social engineering call to the registrar and your protocol is drained. DNSSEC adoption is still embarrassingly low
registrar_audit_ Balancer lost 238k because their DNS provider got socially engineered. no DNSSEC, no registry lock. 40% adoption among DeFi domains is embarrassing in 2026
the fake wallet connect prompt is the real danger. your hardware wallet says approve, the UI looks identical, and the contract is draining you. hardware doesnt save you from DNS attacks
Tomasz W. right that hardware wallets verify the transaction not the website. if the UI lies your signature lies. the only defense is checking the contract address on etherscan before every approve
tomasz w. exactly. hardware wallets verify the transaction, not the website. if the site is compromised youre signing a real approval for a malicious contract
238k gone because someone flipped a DNS record. hardware wallet doesn’t save you if you’re approving contracts on a fake site
the $238k from a single DNS record change still haunts me. I was using balancer that week and the fake site looked identical down to the favicon
thats the real takeaway. your hardware wallet approves whatever transaction you sign on screen. if the site is fake the approval is fake
dnssec_or_die hardware wallets literally just sign whatever transaction you put in front of them. if the UI lies the signature lies
the scary part is how normal the fake site looked. same ui, same wallet connect prompt. even experienced users would fall for this
this is why i always check the contract address on etherscan before signing anything. saved me during the badger dao attack too
^ real one. most people skip that step because the ui looks legit
checking contract address on etherscan before signing should be muscle memory by now. marco b is right, it actually works
Renata Costa checking contract addresses on etherscan should be muscle memory by now. saved me during badger dao too
always verify contract addresses on etherscan before signing anything. saved my bag during the badger dao DNS attack too. muscle memory saves funds
zachxbt traced 238k to one wallet in under 2 hours. that kind of on-chain forensics is why dns hijacking has terrible roi for attackers long term
phil the issue is dnssec adoption is still under 40% among defi domains. the tooling exists, nobody implements it
registrar_panic_ the scariest part is the fake wallet connect prompt. your hardware wallet says approve, the UI looks right, and the contract is draining you. DNSSEC should be mandatory for every DeFi domain
$238k from a DNS record change. the ROI on social engineering attacks against defi is absurd compared to traditional targets
DNS hijacking costs maybe a few hundred in social engineering and returns 200k+. no smart contract exploit has that kind of ratio
238k from a DNS record change proves ROI on social engineering attacks is absurd compared to tech exploits