Shortly after the Securities and Exchange Commission (SEC) warned investors to question cryptocurrency exchanges about the “substantial risks” of loss or theft of cryptocurrency, including those associated with hacking, Bitfinex reportedly experienced a distributed denial of service (DDoS) attack that paralyzed the exchange.

“We are currently under heavy DDoS. API is also down. We are working on further mitigation,” the exchange tweeted Tuesday.

Noting that “bitcoin made the top-10 most targeted industries list, despite its relatively small size and web presence,” Igal Zeifman, security evangelist at Imperva, said, “This young and exponentially growing industry presents a lucrative opportunity for extortionists and other cybercriminals who are always on the lookout for potentially vulnerable and high-profit targets.”

As bitcoin prices fluctuate, Zeifman expects to see attacks escalate. An “alarming number of attacks” over 100Mbps in Q3, “targeting a relatively high number of cryptocurrency exchanges and services,” was “likely related to a recent spike in the price of bitcoin, which more than doubled in the span of the quarter,” he said. 

Tuesday's DDoS attack against Bitfinex “could have been also launched to manipulate bitcoin prices, something offenders have been known to do,” Zeifman said.