Russian threat actors, specifically the Sandworm group, have targeted Ukrainian organizations and Poland's power sector using living-off-the-land (LotL) tactics and deploying data-wiping malware. The attacks, which began in June 2025, involved minimal malware to reduce detection and included the use of web shells and legitimate tools for reconnaissance and data theft.
The threat actors exploited unpatched vulnerabilities to deploy web shells on public-facing servers, gaining initial access. They then used various tactics, including PowerShell commands, scheduled tasks, and legitimate software, to evade detection and perform reconnaissance. The attacks were characterized by the use of legitimate tools and minimal malware, demonstrating the actors' deep knowledge of Windows native tools.
In addition to LotL tactics, Sandworm deployed multiple data-wiping malware families in June and September 2025, targeting Ukraine's education, government, and grain sectors. The grain sector, a vital economic sector, was targeted to disrupt Ukraine's war economy. The data-wiping malware used included ZeroLot and Sting, with initial access achieved by UAC-0099, who then transferred access to APT44 for wiper deployment. The activity is confirmed to be of Russian origin, with specific attribution to the Sandworm group.
In December 2025, Sandworm targeted Poland's power sector with a new wiper malware called DynoWiper, aiming to disrupt the energy infrastructure. The attack, which occurred on December 29 and 30, 2025, targeted two combined heat and power (CHP) plants and a system managing renewable energy sources. The attack was unsuccessful in causing disruption, and Polish authorities attributed it to Russian services. The attack coincided with the tenth anniversary of Sandworm's 2015 attack on Ukraine's power grid.
A new Russia-aligned threat activity cluster, InedibleOchotense, impersonated ESET in phishing attacks targeting Ukrainian entities starting in May 2025. This campaign involved sending spear-phishing emails and Signal text messages containing links to trojanized ESET installers, which delivered the Kalambur backdoor. InedibleOchotense is linked to the Sandworm (APT44) hacking group and has been observed conducting destructive campaigns in Ukraine, including the deployment of wiper malware ZEROLOT and Sting.
Another Russia-aligned threat actor, RomCom, launched spear-phishing campaigns in mid-July 2025 exploiting a WinRAR vulnerability (CVE-2025-8088) targeting various sectors in Europe and Canada. RomCom also targeted a U.S.-based civil engineering company via a JavaScript loader dubbed SocGholish to deliver the Mythic Agent. The activity has been attributed with medium-to-high confidence to Unit 29155 of Russia's Main Directorate of the General Staff of the Armed Forces of the Russian Federation, also known as GRU. The targeted entity had worked for a city with close ties to Ukraine in the past.
The ESET report noted that other Russian-aligned APT groups also maintained their focus on Ukraine and countries with strategic ties to Ukraine, while also expanding their operations to European entities. Gamaredon remained the most active APT group targeting Ukraine, with a noticeable increase in intensity and frequency of its operations during the reported period. Gamaredon selectively deployed one of Turla’s backdoors, indicating a rare instance of cooperation between Russia-aligned APT groups. Gamaredon’s toolset continued to evolve, incorporating new file stealers or tunneling services.
The cyber attack on the Polish power grid in December 2025 was attributed with medium confidence to a Russian state-sponsored hacking group known as ELECTRUM. The attack targeted distributed energy resources (DERs) and affected communication and control systems at combined heat and power (CHP) facilities and systems managing renewable energy systems. ELECTRUM and KAMACITE share overlaps with the Sandworm cluster, with KAMACITE focusing on initial access and ELECTRUM conducting operations that bridge IT and OT environments. The attackers gained access to operational technology systems critical to grid operations and disabled key equipment beyond repair at the site. The attack was opportunistic and rushed, with the hackers attempting to inflict as much damage as possible by wiping Windows-based devices and resetting configurations. The majority of the equipment targeted was related to grid safety and stability monitoring.
The coordinated attack on Poland's power grid in late December targeted multiple distributed energy resource (DER) sites across the country, including combined heat and power (CHP) facilities and wind and solar dispatch systems. Although the attacker compromised operational technology (OT) systems damaging "key equipment beyond repair," they failed to disrupt power, totaling 1.2 GW or 5% of Poland’s energy supply. Based on public reports, there are at least 12 confirmed affected sites. However, researchers at Dragos, a critical industrial infrastructure (OT) and control systems (ICS) security company say that the number is approximately 30. Dragos attributes the attack with moderate confidence to a Russian threat actor it tracks as Electrum, which, although it overlaps with Sandworm (APT44), the researchers underline that it is a distinct activity cluster. Electrum targeted exposed and vulnerable systems involved in dispatch and grid-facing communication, remote terminal units (RTUs), network edge devices, monitoring and control systems, and Windows-based machines at DER sites. Electrum successfully disabled communications equipment at multiple sites, resulting in a loss of remote monitoring and control, but power generation on the units continued without interruption. Certain OT/ICS devices were disabled, and their configurations were corrupted beyond recovery, while Windows systems at the sites were wiped. Even if the attacks had been successful in cutting the power, the relatively narrow targeting scope wouldn’t have been enough to cause a nationwide blackout in Poland. However, they could have caused significant destabilization of the system frequency. "Such frequency deviations have caused cascading failures in other electrical systems, including the 2025 Iberian grid collapse," the researchers say.
CERT Polska revealed that coordinated cyber attacks targeted more than 30 wind and photovoltaic farms, a private company from the manufacturing sector, and a large combined heat and power plant (CHP) in Poland on December 29, 2025. The attacks were attributed to a threat cluster dubbed Static Tundra, which is linked to Russia's Federal Security Service's (FSB) Center 16 unit. The attacks had a purely destructive objective but did not affect the ongoing production of electricity or the heat supply to end users. The attackers gained access to the internal network of power substations associated with a renewable energy facility to carry out reconnaissance and disruptive activities, including damaging the firmware of controllers, deleting system files, or launching custom-built wiper malware codenamed DynoWiper. In the intrusion aimed at the CHP, the adversary engaged in long-term data theft dating back to March 2025, enabling them to escalate privileges and move laterally across the network. The attackers' attempts to detonate the wiper malware were unsuccessful. The targeting of the manufacturing sector company is believed to be opportunistic, with the threat actor gaining initial access via a vulnerable Fortinet perimeter device. At least four different versions of DynoWiper have been discovered to date. The wiper's functionality involves initializing a pseudorandom number generator (PRNG) called Mersenne Twister, enumerating files and corrupting them using the PRNG, and deleting files. The malware does not have a persistence mechanism, a way to communicate with a command-and-control (C2) server, or execute shell commands, and it does not attempt to hide the activity from security programs. The attack targeting the manufacturing sector company involved the use of a PowerShell-based wiper dubbed LazyWiper that scripts overwrites files on the system with pseudorandom 32-byte sequences to render them unrecoverable. The malware used in the incident involving renewable energy farms was executed directly on the HMI machine. In the CHP plant and the manufacturing sector company, the malware was distributed within the Active Directory domain via a PowerShell script executed on a domain controller. The attacker used credentials obtained from the on-premises environment in attempts to gain access to cloud services, downloading selected data from services such as Exchange, Teams, and SharePoint. The attacker was particularly interested in files and email messages related to OT network modernization, SCADA systems, and technical work carried out within the organizations.
The attack on Poland's energy sector in December 2025 was the first large-scale attack against decentralized energy resources (DERs) like wind turbines and solar farms. The attack occurred during a period when Poland was struggling with low temperatures and snowstorms just before the New Year. Dragos assessed with moderate confidence that the activity reflects tradecraft and objectives in line with the Electrum threat group, which overlaps with Sandworm. Electrum has worked alongside another threat actor, tracked as Kamicite, to conduct destructive attacks against Ukrainian ISPs and persistent scanning of industrial devices in the US. Kamicite gained initial access and persistence against organizations, and Electrum executed follow-on activity. Dragos has tracked Kamicite activities against the European ICS/OT supply chain since late 2024. The attack on Poland's energy sector was significant because it was the first major attack against decentralized energy resources (DERs). There was no evidence that the adversary had full control of the DERs, and there was no attempt to mis-operate these resources. Poland was fortunate because DERs make up a smaller portion of its energy portfolio than some other countries. If this same style of attack happened in the US, Australia, or certain parts of Europe where DERs are more prevalent, it could have been potentially catastrophic for the system. The attack highlighted the ongoing threat faced by the energy sector, with threat actors gaining initial access through vulnerable Internet-facing edge devices before deploying wipers that damaged remote terminal units (RTUs). CISA advised OT operators to prioritize updates that allow firmware verification and to immediately change default passwords on things like edge devices. Dragos recommended that organizations ensure architecture is defensible through methods like strict authorization practices, OT/IT segmentation, strict vendor access governance, secure remote access, and ICS network visibility and monitoring.