Decoy ICS/SCADA Water Utility Networks Hit By Attacks

It took only a few hours before attackers started to hammer away at two decoy water utility networks stood up in a recent experiment that resulted in 39 attacks from 14 different nations over a 28-day period.

Researchers at Trend Micro built two honeypot-based architectures that mimic a typical ICS/SCADA environment, including one that included a Web-based application for a water pressure station. The goal was to determine what kinds of attacks and attackers are going after ICS/SCADA systems today, and the researchers were a bit surprised by some of what they saw.

Kyle Wilhoit, a researcher with Trend Micro who led the experiment, found that most attacks on ICS/SCADA systems appeared to come from China (35 percent), followed by the U.S. (19 percent) and Laos (12 percent).

"I had initially anticipated normal drive-by, automated attacks, not really any type of attack going in and trying to modify these systems. But it obviously went much differently," he says. "We got attacked quite a bit more and in different ways than we anticipated."

Had the honeypot-based ICS/SCADA systems been real, the attackers would have been able to compromise the water system, stop the pump altogether, or modify its pressure in the attacks, he says. "I also put in the ability to modified what they perceived as the actual temperature of the water output: If they wanted to make it 170 degrees Fahrenheit, they could do that. That was an interesting thing I threw in ... there were some attempts," says Wilhoit, who first reported the findings at Black Hat Europe last week.

Wilhoit, who previously worked at an energy company and has experience with ICS/SCADA systems, says the phony systems were built to appear as real ICS/SCADA systems, including the typically weak security and accessibility via the Internet. "They were initially designed to mimic ICS/SCADA systems to a 't,'" Wilhoit says. "They look identical to those systems in almost every way possible, so that way it was realistic."

[Existing process of vulnerability reporting, patching doesn't go far enough in improving the overall security of critical infrastructure systems, SCADA experts say. See ICS-CERT, SCADA Patching Under The Microscope.]

Francis Cianfrocca, CEO at Bayshore Networks, says his company has conducted similar experiments over the past three years and come to similar conclusions. "We should not at all be surprised that there's active reconnaissance by attackers out there," he says. "If there are a few people [in ICS/SCADA] left who were not scared before, they should be now."

Trend Micro built a total of three honeypots for the experiment, which it's still running today -- with a few modifications now that the cat's out of the bag -- including one high-interaction and one low-interaction honeypot. Wilhoit says the high-interaction network uses real SCADA devices, including a PLC running on a virtual instance of Ubuntu on Amazon EC2. It's set up as a Web page of a "water pressure station."

The low-interaction honeypot network is a software-based emulation of a SCADA system. "It's a different way of deploying a honeypot that's cheaper and virtually available from anywhere ... In total, we did three honeypots in the U.S.," he says.

Of the 39 attacks the honeypots suffered, 12 were unique and targeted, and 13 were repeated by several of the attackers.

The attackers were going after Modbus TCP and TCP port 502 in many cases, according to Trend's findings via Snort. "The top Snort alert generated in the honeypot environment was Modbus TCP non-Modbus communication on TCP port 502. This rule is triggered when an established connection utilizing Modbus is hijacked or spoofed to send other commands or attacks to a different device," according to the report. Snort also flagged unauthorized read and write requests to PLCs, it says.

"These rules are traditionally triggered when an unauthorized Modbus client attempts to read or write information from or to a PLC or SCADA device. Both of these rules traditionally indicate that ICS network reconnaissance is occurring—the first step in ICS network exploitation," according to the report. Those alerts came from attackers out of the U.S., Russia, and China, and were not the result of port scans but rather targeted communiques, the report says.

Wilhoit says he did not include port scans or SQL injection-type attack vectors to ensure he was focusing on truly targeted attacks, not wide-net ones.

Among the specific attacker activities, the U.S. attacks included modifying the CPU fan speed of the phony water pump as well as Modbus traffic modification. The attackers out of China used a spearphishing attack and went after statistics, diagnostics, and protocols; the attackers out of Russia used malware and went after statistics, diagnostics, and protocols, for instance.

"The spearphishing email [from China] that the admin received was a big surprise. That was nothing that I had anticipated seeing," Wilhoit says. And that, of course, fits the popular modus operandi of Chinese targeted attackers, he notes.

But Bayshore's Cianfrocca says you can't read too much into the regional attribution of the attacks. "That's not terribly meaningful. Anyone who is really determined is using anonymizers," he says.

Still, the experiment demonstrates that ICS/SCADA attacks are ongoing and active. "This research proves stuff is going on. With what [regularity], I don't know. Maybe companies aren't disclosing those attacks, and a lot of these companies may not be aware that they are being attacked and targeted," Wilhoit says.

The keys to protecting these systems, he says, are at the least to use two-factor authentication wherever you can with critical systems and refrain from letting any critical devices face the Internet. "If you couple those two things, that should cut down quickly your threat profile from an attacker standpoint," Wilhoit says.

And SCADA attackers typically aren't your typical hackers. "The [ICS/SCADA] attack surface is extremely large compared to enterprise IT surface ... there are a number of different kinds of different systems, hundreds of different controllers, and the systems are a lot more arcane and hard to get to know. You have to be kind of a specialist, at least an electric engineer or a chemical engineer if you are attacking a chemical plant," Bayshore Networks' Cianfrocca says. "This points to a more rarified kind of attacker that's more knowledgeable, more determined, and better funded, probably working for a government somewhere. And when they do find a hole to poke, it causes a lot of damage."

The full Trend Micro report is available here (PDF) for download.

Have a comment on this story? Please click "Add Your Comment" below. If you'd like to contact Dark Reading's editors directly, send us a message.