A digital thief used insider access to a Canadian Internet service provider's network to hijack the efforts of at least 51 cryptocurrency mining groups and stole the payouts from individual miners who participated in the pools, according to a report by managed security service Dell Secureworks.
The attack, which started with initial tests in early February and lasted about four months, redirected machines conducting mining to cyber-criminal-owned mining pools, essentially stealing individuals' efforts and profiting from their computers' work. The operation netted at least $83,000 for the thief, or thieves, behind the operation, Secureworks stated in an analysis of the attack.
Cryptocurrency mining involves intensive calculations that require enormous computing resources, so miners of Bitcoins, Dogecoins and other such currencies have pooled their resources to do the calculations and receive a portion of the digital coins paid out based on their level of contribution. But on March 22, a number of miners started complaining that they were not getting any funds.
"People were noticing that their payouts [were] not happening that day," Stewart said. "But not everyone monitors their payouts, so it went unnoticed for a while."
The key to the attack involved sending out updates to the Internet infrastructure using the Border Gateway Protocol (BGP), which Internet service providers use to advertise the best route to systems in their network.
The attacker, which had privileged access on a Canadian ISP's network, sent out updates to reroute the network address of the targeted mining pool to his own network, and then used a redirect command particular to the pool software to redirect individual miners to the cyber-criminal's pool.
BGP attacks are rare and usually caused by operator error. In 2010, a BGP update issued by China Telecom routed traffic from 37,000 networks—which could have accounted for up to 15 percent of the world's traffic—to that country's network. In 2008, the government of Pakistan abused its trusted position on the Web by issuing a BGP update for YouTube's network to block videos that it considered offensive.
The attack on cryptocurrency mining underscores the danger of BGP hijacking and the importance for companies to check any updates to their routers. The attacker could just as easily have targeted corporate networks, sending BGP updates to the Internet service providers on which businesses rely.
"Network administrators need to watch their routes and make sure that someone is not broadcasting on it," Stewart said. "It could be accidental, and not malicious, but that won't matter if your company is taken offline."
Dell Secureworks contacted the Canadian ISP in May, and the attack traffic stopped within three days. The company did not name the ISP and said that no explanation was provided.