Researchers from Kaspersky Lab’s Industrial Control Systems Cyber Emergency Response Team (ICS CERT) have found significant overlaps in GreyEnergy and Zebrocy activity, both of which were previously linked to Russia.
GreyEnergy is a threat actor that is believed to be a successor of the notorious BlackEnergy group and experts estimate that it has been around for more than three years. GreyEnergy has conducted espionage and reconnaissance activities against organizations in the energy and transportation sectors, mainly in Ukraine and Poland.
GreyEnergy uses a modular piece of malware that has a wide range of backdoor and data theft capabilities. While none of its modules specifically target ICS, the threat group has been observed attacking industrial workstations and SCADA systems.
Zebrocy, on the other hand, is a Trojan used by the Russia-linked cyberspy group known as Sofacy, APT28, Fancy Bear, Pawn Storm, Sednit and Strontium. Zebrocy has been used since 2017 against targets in the Middle East, Asia and Europe.
According to Kaspersky, both GreyEnergy and Zebrocy were actively used at around the same time against the same organizations. Researchers have identified the same command and control (C&C) server IP addresses being used by both pieces of malware to download additional components. The IPs belonged to servers in Ukraine and Sweden, and they were used simultaneously by both threats in June 2018.
Furthermore, the security firm says both GreyEnergy and Zebrocy have been used to target a number of industrial companies in Kazakhstan. One of these targets received a spear-phishing document on June 21, 2018, and a Zebrocy spear-phishing document roughly one week later. These documents were similar and purported to come from Kazakhstan’s Ministry of Energy.
“Though no direct evidence exists on the origins of GreyEnergy, the links between a Sofacy subset known as Zebrocy and GreyEnergy suggest that these groups are related, as has been suggested before by some public analysis,” Kaspersky researchers explained.
In May 2018, the FBI’s attribution of the VPNFilter attack to Russia suggested that both Sofacy and TeleBots (aka Sandworm), another successor of BlackEnergy, had collaborated on the attack. Security firms contacted by SecurityWeek at the time said they had no reason to question the FBI’s assumption that there had been a link between Sofacy and Telebots, and Kaspersky noted at the time that the two threat actors had been known to overlap.
“The compromised infrastructure found to be shared by these two threat actors potentially points to the fact that the pair not only have the Russian language in common, but that they also cooperate with each other,” Maria Garnaeva, security researcher at Kaspersky Lab ICS CERT, said on Thursday.
“It also provides an idea of their joint capabilities and creates better picture of their plausible goals and potential targets. These findings add another important piece into public knowledge about GreyEnergy and Sofacy. The more the industry knows about their tactics, techniques and procedures, the better security experts can do their job in protecting customers from sophisticated attacks,” Garnaeva added.