New Malware Tools Pose 'Clear and Present Threat' to ICS Environments

The US Cybersecurity and Infrastructure Security Agency (CISA), along with the NSA, FBI, and others, this week urged critical infrastructure organizations — especially in the energy sector — to implement defenses against a set of highly sophisticated cyberattack tools designed to target and disrupt industrial environments.

The warning applies particularly to ICS and OT networks using programmable logic controllers (PLCs) from Schneider Electric and Omron and servers based on Open Platform Communications Unified Architecture (OPC UA). The advisory was prompted by the recent discovery of three malware tools custom-built to target these technologies and manipulate them in dangerous and potentially destructive ways. However, the malware can be adapted to attack other ICS technologies as well.

CISA's advisory contained a series of mitigation measures that it recommended organizations implement proactively to reduce exposure to the new threat.

Mandiant analyzed the new attack tools recently in partnership with Schneider and is collectively tracking them under the name INCONTROLLER. In a report this week, the security vendor described the malware as having an "exceptionally rare and dangerous" capability and posing a critical risk to organizations that use the targeted equipment. Mandiant compared INCONTROLLER to previous ICS-specific threats such as Stuxnet, which was used to destroy hundreds of centrifuges at an Iranian nuclear-enrichment facility in 2010, and Industroyer, which caused a power outage in Ukraine in 2016.

Work of a Russian State-Sponsored Group?
"We believe INCONTROLLER is very likely linked to a state-sponsored group given the complexity of the malware, the expertise and resources that would be required to build it, and its limited utility in financially motivated operations," says Rob Caldwell, director of industrial control systems and operational technology at Mandiant. He says Mandiant has been unable to associate the malware with any previously tracked group but believes those behind it are most likely Russia-linked. "While our evidence connecting INCONTROLLER to Russia is largely circumstantial, we note it given Russia's history of destructive cyberattacks, its current invasion of Ukraine, and related threats against Europe and North America."

Mandiant identified one of the attack tools as "Tagrun," a tool for scanning OPC environments, enumerating OPC servers, harvesting data from them, and brute-forcing credentials. The security vendor identified the tool as likely used for conducting reconnaissance on industrial networks. Mandiant has dubbed the second tool as "Codecall," which it described as a framework that uses two common industrial protocols — Modbus and Codesys — to communicate and interact with at least three Schneider PLCs. The malware can identify Schneider and other Modbus-enabled devices on a network and connect to them using the two protocols. The third tool, "Omshell," targets Omron PLCs via HTTP, Telnet, and a proprietary Omron protocol. It is designed to interact with a mechanism on Omron devices for monitoring the safe running of so-called servo motors used in industrial applications. The malware can gain shell access to Omron PLCs and take a variety of malicious actions, including wiping device memory, resetting a device, loading backup data, and executing arbitrary code on it.

Collectively the malware tools have capabilities that allow attackers to surveil and collect data from target industrial environments that they can then use to identify high-value systems and to launch potentially catastrophic attacks against them in industrial settings. Potential attack scenarios include threat actors using Omshell and/or Codecall to crash targeted PLCs and disrupt operations; sending malicious commands to PLCs to sabotage industrial processes; or disabling safety controllers to cause physical destruction in a plant or industrial setting.

"The components of INCONTROLLER contain more sophisticated methods of interacting with and attacking or modifying the targeted devices than seen in previous ICS-specific malware," Caldwell says. These components are designed to make interaction with PLC devices easy for attackers with little detailed knowledge of the targeted ICS protocols. "Further, these components are modular and could be extended to target additional devices or add additional capabilities," he says.

Mandiant said it is also tracking two other tools targeted at Windows-based systems that appear to be related to INCONTROLLER activity. One of them exploits a known vulnerability, CVE-2020-15368, to install and exploit a vulnerable driver on target systems, and the other is a backdoor that enables reconnaissance activity. The tools could be used to support a threat actor's broader goals in an industrial cyberattack, Mandiant said.

A Clear and Present Danger to Industrial Environments
ICS security vendor Dragos listed a total of 16 devices and software tools from Omron and Schneider that it said the malware was designed to interact with and exploit. The technologies are used in a wide range of industry verticals. But Dragos said its analysis of the malware suggests it is targeted mostly at equipment in liquefied natural gas (LNG) and electric power environments.

Dragos is collectively tracking the attack tools as "PIPEDREAM" and the threat actors behind it as "CHERNOVITE." A whitepaper that the company released this week on the threat identified the threat actor as having the ability — among other things — to manipulate the torque and speed of Omron servo motors in a way that could cause enough physical destruction to result in loss of life. Dragos' whitepaper listed several other malicious actions that threat actors could use the malware for, including triggering denial of control and denial for view for ICS operators; disrupting operating technology by masquerading as a trusted process; disabling process controllers to extend time-to-recovery from an incident; and undermining authentication and encryption mechanisms in OT environments.

"PIPEDREAM is a clear and present threat to the availability, control, and safety of industrial control systems and processes endangering operations and lives," Dragos said.

News of the malware tools comes just days after reports of Ukraine's computer emergency response team (CERT-UA) thwarting an effort by Russia's Sandworm group to disrupt the country's power grid using Industroyer, one of the first known malware tools targeted specifically at the electric grid. So far, researchers have discovered at least seven highly sophisticated ICS-specific attack tools, which include Stuxnet, Industroyer, Triton, and BlackEnergy.

Danielle Jablanski, OT cybersecurity strategist at Nozomi Networks, says the combined tools in this case were built to search for specific devices, to understand their operational parameters, to gain credentialed access, and to remotely control various legitimate functions of the devices for their intended objectives. "These are customizable based on the devices targeted but can be modified to target additional devices that leverage the same protocols," she says.

Jablanski says that options for thwarting attacks become scarce when threat actors have the credentials and know how to use devices based on their design, protocols, and features.

It's presently unclear in what host environment the newly discovered tools were found. But typically, some stop-gap measures for mitigating exposure to the threat would include disabling unnecessary functionality, introducing access controls to limit legitimate users who communicate with the device, and taking password management seriously. "Device hardening to limit the susceptibility and severity of cyber incidents is a staple of defense in depth strategies across ICS/OT environments," she says.

Eric Byres, CEO of aDolus Technology, says the new tools highlight a recent trend away from previous attacks where threat actors gained access to an OT environment by leapfrogging to it from the IT network. Those kinds of attacks have become less common with many organizations tightening OT security. So, sophisticated attackers are finding other ways to establish access to their victims' OT networks, he says pointing to Stuxnet as an example.

"Stuxnet did it through a combination of infected USB flash drives, printer sharing, and modified PLC logic files," he says. Similarly, Dragonfly, which was Russian in origin, attacked the manufacturers of OT control equipment and replaced the software they supplied to their industrial customers with trojanized versions.

"These supply chain-driven attacks are now becoming the preferred method for nation-state attackers, especially the Russian spy agencies," Byres says. "By going after OT suppliers rather than the OT systems directly, they get tremendous multiplication effects."