Users of MyEtherWallet, a web app for storing and sending ether and ethereum-based tokens, experienced an attack Tuesday that saw users of the service lose around $152,000 worth of ether.
The company was quick to alert users to the danger, tweeting a warning at 7:29 a.m. EDT, within 15 minutes of when the hack began:
Couple of DNS servers were hijacked to resolve http://myetherwallet.com users to be redirected to a phishing site. This is not on @myetherwallet side, we are in the process of verifying which servers to get it resolved asap.
MyEtherWallet.com: Your Key to Ethereum
Free, open-source, client-side Ethereum wallet. Enabling you to interact with the blockchain easily & securely.
Even so, users took to social media to report that they were losing funds.
“Went on to myetherwallet and saw that myetherwallet had [an] invalid connection certificate in the corner,” rotistain posted to the wallet’s subreddit around 8:30 a.m. EDT, adding:
“As soon as I logged in, there was a countdown for about 10 seconds and A tx was made sending the available money I had on the wallet to another wallet ‘0x1d50588C0aa11959A5c28831ce3DC5F1D3120d29.’ I have no idea what happened.”
Micky Socaci, lead developer at BlockBits.io, explained the attack in a post to the ethereum subreddit.
“Do not use myetherwallet.com if you’re using Google Public DNS (126.96.36.199 / 188.8.131.52) at this moment,” he wrote, adding: “It seems these DNS servers are resolving the domain to a bad server that CAN steal your keys!”
His explanation fits with MyEtherWallet’s assertion that the attack was not on their side. Domain Name System (DNS) servers resolve website URLs to the appropriate IP addresses.
Money on the move
As of press time, the affected funds are being shuffled around and broken into smaller increments, according to data from blockchain information provider Etherscan.
Initially, the Etherscan block explorer showed 0x1d50588C0aa11959A5c28831ce3DC5F1D3120d29 as having received 179 inbound transactions starting from 7:17 a.m. and totaling 216.06 ether, or nearly $152,000 at the time of writing.
The attacker sent 215 ether to another address, 0x68ca85dbf8eba69fb70ecdb78e0895f7cd94da83, at 10:15 a.m. Since then, the funds have been split further, with increments being divided between multiple wallet addresses.
According to MyEtherWallet CEO Kosala Hemachandra, “all the DNS servers are resolving back to correct addresses.”
“But I want to wait another [hour] or so,” he added during a conversation on Skype.
Hemachandra said that the hackers were apparently “large enough to do a DNS poisoning attack on Google public DNS servers, which made it cache a malicious IP address for myetherwallet.com.” Google fixed the issue “in a very short time,” he went on to say.
“It is really unfortunate, we live in a world where even the most secured websites are prone to this kind of attacks,” Hemachandra told CoinDesk. “I am sad about this and I hope MEW team will be able to educate users and convince them [to] use hardware wallets and local versions of MEW
Google’s press office did not immediately respond to a request for comment.