RIG EK Remains Top of Heap, Turns to Cryptomining

Even after a precipitous drop in activity last quarter, security researchers say that the RIG Exploit Kit (RIG EK) still leads the pack when it comes to overall malicious campaigns. And some of them have found that the crooks are expanding their moneymaking horizons by using RIG to take advantage of the cryptocurrency craze bubbling the market for Bitcoin and other currencies. The exploit kit is being used by the bad guys in a new malicious campaign to distribute coin miners through drive-by downloads that they say likely signals another wide-scale evolution in the cybercriminal enterprise.

"There isn’t a day that goes by without a headline about yet another massive spike in Bitcoin valuation, or a story about someone mortgaging their house to purchase the hardware required to become a serious cryptocurrency miner," writes Jérôme Segura, lead malware intelligence analyst for Malwarebytes Labs in a new report this week. "As cryptocurrencies become more and more popular, we can only expect to see an increase in malicious coin miners, driven by the prospect of financial gains and increased anonymity."

According to Segura, the bad guys are leveraging RIG in a new campaign called Ngay that distributes droppers containimg one or more coin miner malware for cryptocurrencies like Monero and Electroneum. While some might write off these kinds of exploit kit payloads as less risky than a banking Trojan, Segura says their long-term impact is still serious.

"Not only can existing malware download additional payloads over the course of time, but the illicit gains from cryptomining contribute to financing the criminal ecosystem, costing billions of dollars in losses," he says.

Overall, RIG remains one of the most prevalent exploit kits to distribute any kind of malicious payload online, not just coin miners. According to a report out today by Zscaler, this leading position was maintained in spite of a pretty sizable drop in activity last quarter. 

"We saw an approximate drop in weekly activity of 63% between October and November 2017. RIG EK has been active at about the same volume of activity into January 2018 since the end of October," Derek Gooley, senior security researcher for Zscaler told Dark Reading. "RIG maintained a fairly constant level of activity throughout the summer (of 2017), which is what made this recent drop of observed activity stand out."

The Ngay campaign is not necessarily the first to have RIG EK or other exploit kits distribute coin miners, but it does offer an anecdotal touchstone for where researchers expect things to go in the next year.  

"Cryptocurrency mining payloads delivered by exploit kits are becoming increasingly common," Gooley wrote in his report. "Earlier this fall we observed a one-off RIG campaign that used a different malicious redirect structure than the common RIG campaigns to deliver the exploit kit. This campaign infected victims with the Dofoil Trojan, which then installed the malicious BitCoinMiner cryptocurrency mining tool."

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