
ESET linked a late-2025 cyberattack on Poland’s energy system to the Russia-linked Sandworm APT.
“Based on our analysis of the malware and associated TTPs, we attribute the attack to the Russia-aligned Sandworm APT with medium confidence due to a strong overlap with numerous previous Sandworm wiper activity we analyzed,” said ESET researchers. “We’re not aware of any successful disruption occurring as a result of this attack,” ESET researchers said.
ESET researchers uncovered DynoWiper, a destructive wiper malware used in an attempted cyberattack against Poland’s energy sector on December 29, 2025. While no successful disruption has been confirmed, the malware’s architecture shows clear destructive intent. ESET attributes the operation with medium confidence to the Russia-aligned Sandworm APT group, citing strong overlaps in tactics, techniques, and behavior with previous Sandworm-linked wiper attacks analyzed by the team.
The attack struck during peak winter and the 10‑year anniversary of Sandworm’s 2015 attack on 🇺🇦 Ukraine’s power grid – the first malware-driven blackout, leaving ~230,000 people without electricity. 3/5
— ESET Research (@ESETresearch) January 23, 2026
The attempted attack occurred during peak winter demand and coincided with the 10-year anniversary of Sandworm’s 2015 cyberattack on Ukraine’s power grid, the first malware-induced blackout that left around 230,000 people without electricity. ESET tracks the DynoWiper malware as Win32/KillFiles.NMO. Subscribers to ESET’s private Threat Intelligence APT reports have already received further technical details and indicators of compromise to aid rapid detection and incident response. The cybersecurity firm also shared an associated IoC hash for defensive use.
“Fast forward a decade and Sandworm continues to target entities operating in various critical infrastructure sectors, especially in Ukraine.” concludes the report. “In their latest APT Activity Report, covering April to September 2025, ESET researchers noted that they spotted Sandworm conducting wiper attacks against targets in Ukraine on a regular basis.”
The Sandworm group (aka BlackEnergy, UAC-0082, Iron Viking, Voodoo Bear, and TeleBots) has been active since 2000. It operates under the control of Unit 74455 of the Russian GRU’s Main Center for Special Technologies (GTsST). The group is also the author of the NotPetya ransomware that hit hundreds of companies worldwide in June 2017. In 2022, the Russian APT used multiple wipers in attacks aimed at Ukraine,including AwfulShred, CaddyWiper, HermeticWiper, Industroyer2, IsaacWiper, WhisperGate, Prestige, RansomBoggs, and ZeroWipe.
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