ZionSiphon Malware Targets ICS in Water Facilities

Researchers at Darktrace have discovered a new malware strain named ZionSiphon, which appears to target water treatment and desalination plants in Israel.  ZionSiphon has many capabilities typically seen in commodity malware, but it caught analysts’ attention due to functionality aimed at operational technology (OT), specifically industrial control systems (ICS). Strings in the analyzed malware sample indicate that ZionSiphon has been developed by anti-Israel hackers, and one encoded string decodes to “Poisoning the population of Tel Aviv and Haifa”. There are several other indicators that Israel is the malware’s main target, including strings naming water facilities in the country. In addition, once it verifies that it’s running with admin privileges and establishes persistence, the malware executes a function to fetch the local IP address and determine whether the compromised host is located in Israel. If the IP is associated with Israel, ZionSiphon checks the system for processes and folders typically found in water treatment plants. Specifically, the malware looks for processes linked to reverse osmosis, desalination, chlorine handling, and plant control. If these conditions are met, the malware looks for local configuration files associated with the aforementioned water treatment processes and attempts to alter them to increase chlorine doses and pressure. It then scans the network for ICS devices that use the Modbus, DNP3, and S7comm protocols. The code indicates that if Modbus devices are found, the malware would attempt to tamper with parameters associated with chlorine doses and pressure. The payload only activates if the country is Israel and the system is associated with a water treatment plant. If these conditions are not met, the malware deletes itself from the device. Researchers also found a mechanism that enables the malware to spread via USB drives. While ZionSiphon seems to have extended capabilities, Darktrace researchers have identified issues in the country validation functionality and incomplete logic for the targeting of DNP3 and S7comm protocols, indicating that the malware is under development. Moreover, the local configuration file tampering and Modbus parameter modifications are unlikely to have an impact in a real-world environment. The code points to the intent to cause disruption, but lacks the sophistication needed to actually change chlorine levels in practice. “Even in its unfinished state, ZionSiphon underscores a growing trend in which threat actors are increasingly experimenting with OT‑oriented malware and applying it to the targeting of critical infrastructure,” Darktrace said. The water sector has been a prime target for hackers. Industrial control systems and other OT systems in this sector are often exposed to the internet and left unprotected, and the potential impact of such attacks can be significant. This makes them an attractive target for many hacktivist groups and state-sponsored threat actors posing as hacktivists.  Israel’s water sector in particular is regularly targeted by Iranian hackers. Pro-Israel hackers have also been known to target water facilities in other countries.  The emergence of ZionSiphon is not surprising in light of the US-Israel-Iran conflict, which has led to an increase in cyberattacks.  Related: Iran-Linked Hackers Disrupt US Critical Infrastructure via PLC Attacks Related: Rockwell Vulnerability Allowing Remote ICS Hacking Exploited in Attacks Related: Ramnit Malware Infections Spike in OT as Evidence Suggests ICS Shift Related: Default ICS Credentials Exploited in Destructive Attack on Polish Energy Facilities WRITTEN BY Eduard Kovacs Eduard Kovacs (@EduardKovacs) is senior managing editor at SecurityWeek. He worked as a high school IT teacher before starting a career in journalism in 2011. 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