The Bitcoin network is being hammered by a massive spam attack, and the targets now include WikiLeaks and Voat, the upstart Reddit clone that became a home for Redditors fleeing the site after new anti-harassment policies were instituted.
The onslaught began earlier this week, when thousands of tiny Bitcoin transactions—called "dust"—were sent across the network by an unknown attacker in an apparent attempt to bog down the system with junk. In an effort to clean it up, a large Chinese mining pool generated the biggest Bitcoin transaction ever made on Tuesday. But it wasn't enough. The mayhem was so that some users reported transactions taking up to 14 hours to be confirmed. The usual timeframe is somewhere around 10 minutes.
Still, the prevailing mood among experts was that things could be worse. Apparently someone forgot to knock on wood, because today, shit got really, really real. During Tuesday's attack, the dust transactions were sent to wallets with well-known addresses and keys, making cleanup a snap for miners. Today, dust transactions are being sent to parties like WikiLeaks and Voat.
"It is clear that there are multiple spamming motifs going on"
"Overall, quite impressive," said UC Berkeley computer security researcher Nicholas Weaver of the current attack in an email. "But I can still think of things that could further increase the effectiveness of the attacks."
For example, attackers could add a little reward to their junk transactions so that miners—the people who process blocks of transactions and load them on to the blockchain—will be incentivized to process the spam first, leaving real transactions out.
Why WikiLeaks and Voat? That's anybody's guess. The worst that can happen—aside from increasing the overall load on the Bitcoin network, which appears to be the chief goal—is that thousands of tiny transactions being sent to their wallets will probably be really annoying. Think having a wallet full of pennies is bad? Just imagine if your wallet was full of thousands of them. Hey, there's a reason Canada got rid of the little copper shits.
A blockchain analysis of the wallets involved in spamming WikiLeaks reveals that the amounts allocated to this attack are astronomical compared to those involved in the previous round. While an estimated three bitcoins, roughly $800, was spent on spam on Tuesday, it appears as though at least 30 or more bitcoins—more than $8,000—was involved in the attack that sent dust to WikiLeaks' wallet, among others. Three bitcoins being sent .00001 Bitcoin at a time is a lot of spam, but 30? Now that's a lot of spam.
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Although it is difficult to be sure, thanks to the possible use of multiple wallets, the wallets involved in sending dust to Voat appear to contain much less.
The identity of the person, or people, behind the attack is a mystery. Could it be rogue developers? Vigilantes out to test the system? Someone who has a bone to pick with the powerful Chinese mining pools that control the majority of the Bitcoin network's processing power? The new targets, as well as the vastly different amounts apparently allocated to the different attacks, adds further confusion as to who could be involved.
"It is clear that there are multiple spamming motifs going on," Weaver said, "but whether it's one group trying multiple things or multiple independent groups is unknown at this time."