Dangerous ICS Malware Targets Orgs in Russia and Ukraine

Two dangerous malware tools targeted at industrial control systems (ICS) and operating technology (OT) environments in Europe are the latest manifestations of the cyber fallout from the war in Ukraine.

One of the tools, dubbed "Kapeka," appears linked to Sandworm, a prolific Russian state-backed threat actor that Google's Mandiant security group this week described as the country's primary cyberattack unit in Ukraine. Security researchers from Finland-based WithSecure spotted the backdoor featured in 2023 attacks against an Estonian logistics company and other targets in Eastern Europe and perceive it as an active and ongoing threat.

Destructive Malware

The other malware — somewhat colorfully dubbed Fuxnet — is a tool that Ukraine government-backed threat group Blackjack likely used in a recent, destructive attack against Moskollector, a company that maintains a large network of sensors for monitoring Moscow's sewage system. The attackers used Fuxnet to successfully brick what they claimed was a total of 1,700 sensor-gateways on Moskollector's network and in the process disabled some 87,000 sensors connected to these gateways.

"The main functionality of the Fuxnet ICS malware was corrupting and blocking access to sensor gateways, and trying to corrupt the physical sensors as well," says Sharon Brizinov, director of vulnerability research at ICS security firm Claroty, which recently investigated Blackjack's attack. As a result of the attack, Moskollector will likely have to physically reach each of the thousands of affected devices and replace them individually, Brizinov says. "To restore [Moskollector's] ability of monitoring and operating the sewage system all around Moscow, they will need to procure and reset the entire system."

Kapeka and Fuxnet are examples of the broader cyber fallout from the conflict between Russia and Ukraine. Since the war between the two countries started in February 2022 — and even well before that — hacker groups from both sides developed and used a range of malware tools against each other. Many of the tools, including wipers and ransomware, have been destructive or disruptive in nature and mainly targeted critical infrastructure, ICS, and OT environments in both countries.

But on several occasions, attacks involving tools spawned from the long-standing conflict between the two countries have affected a broader swath of victims. The most notable example remains NotPetya, a malware tool that the Sandworm group originally developed for use in Ukraine, but which ended up impacting tens of thousands of systems worldwide in 2017. In 2023, the UK's National Cyber Security Centre (NCSC) and the US National Security Agency (NSA) warned of a Sandworm malware toolset dubbed "Infamous Chisel" posing a threat to Android users everywhere.

Kapeka: A Sandworm Replacement for GreyEnergy?

According to WithSecure, Kapeka is a novel backdoor that attackers can use as an early stage toolkit and for enabling long-term persistence on a victim system. The malware includes a dropper component for dropping the backdoor on a target machine and then removing itself. "Kapeka supports all basic functionalities that allow it to operate as a flexible backdoor in the victim's estate," says Mohammad Kazem Hassan Nejad, a researcher at WithSecure.

Its capabilities include reading and writing files from and to disk, executing shell commands, and launching malicious payloads and processes including living-off-the-land binaries. "After gaining initial access, Kapeka's operator can utilize the backdoor to perform a wide variety of tasks on the victim's machine, such as discovery, deploying additional malware, and staging next stages of their attack," Nejad says.

According to Nejad, WithSecure was able to find evidence suggesting a connection to Sandworm and the group's GreyEnergy malware used in attacks on Ukraine's power grid in 2018. "We believe Kapeka may be a replacement for GreyEnergy in Sandworm's arsenal," Nejad notes. Though the two malware samples do not originate from the same source code, there are some conceptual overlaps between Kapeka and GreyEnergy, just as there were some overlaps between GreyEnergy and its predecessor, BlackEnergy. "This indicates that Sandworm may have upgraded their arsenal with new tooling over time to adapt with the changing threat landscape," Nejad says.

Fuxnet: A Tool to Disrupt and Destroy

Meanwhile, Claroty's Brizinov identifies Fuxnet as ICS malware intended to cause damage to specific Russian-made sensor equipment. The malware is meant for deploying on gateways that monitor and collect data from physical sensors for fire alarms, gas monitoring, lighting, and similar use cases.

"Once the malware is deployed, it will brick the gateways by overwriting its NAND chip and disabling external remote access capabilities, preventing operators from remotely controlling the devices," Brizinov says.  

A separate module then attempts to flood the physical sensors themselves with useless M-Bus traffic. M-Bus is a European communications protocol for remotely reading gas, water, electric, and other meters. "One of the main purposes of Blackjack’s Fuxnet ICS malware [is] to attack and destroy the physical sensors themselves after gaining access to the sensor gateway," Brizinov says. To do so, Blackjack chose to fuzz the sensors by sending them an unlimited number of M-Bus packets. "In essence, BlackJack hoped that by endlessly sending the sensor random M-Bus packets, the packets would overwhelm them and potentially trigger a vulnerability that would corrupt the sensors and place them in an inoperable state," he says.

The key takeaway for organizations from such attacks is to pay attention to the security basics. Blackjack, for instance, appears to have gained root access to target sensor-gateways by abusing weak credentials on the devices. The attack highlights why it "is important to uphold a good password policy, making sure devices do not share the same credentials or use default ones," he says. "It is also important to deploy good network sanitization and segmentation, making sure attackers would not be able to move laterally inside the network, and deploy their malware to all edge devices."