Cryptocurrency continues to change the world of money. Bitcoins and blockchain technology might replace traditional banking, but first it is the community who have to solve a lot of security problems. Bitcoin wallets and companies are being targeted by the criminals more and more as they face easier schemes to launder stolen funds. Traditional banks have controls to detect and prevent laundering schemes but in the crypto currency world we face bitcoin mixers that make the tracking of stolen funds a complicated challenge. It is quite a show as we watch cybercriminals find themselves victims of their own community when new attacks target bitcoin companies and wallet users.
This week the DNS server records for blockchain.info and blockchain.com were hijacked. An attack of this sort is a departure from the normal uprise we’re tracking in email phishing attempts and abused advertising services to acquire user credentials. Because these DNS Hijacking attacks seem to be quite popular and effective, we have a system to monitor the records large set of popular domain names. We wrote massresolver, a simple tool leveraging libunbound to quickly and securely resolve a massive list of domain names, even with an empty cache.
We detected the change in nameservers early in the morning
IP addresses were changed:
Company shortly discovered the issue with DNS
About an hour later one of the reddit users noticed the same and posted a new thread on the bitcoin subreddit
Both sites acknowledged that their DNS was hijacked and they were able to restore all services
OpenDNS is blocking both IPs so our customers, who use bitcoins, would not be exposed to the risk. In this case no damage or hack was done to the servers of the targeted companies, but attackers were able to change DNS records to redirect users to a totally different set of machines. And controlling a domain name also allows attackers to potentially gather credentials of the wallets. So treat your bitcoin wallet as your real one, and be aware of the ongoing malicious campaigns.