A Russian national accused of participating in a cyber espionage campaign targeting Western organizations, including U.S. and European companies and NATO-aligned government agencies, pleaded not guilty Thursday to federal charges. Denis Obrezko, who was extradited from Thailand last month, entered his plea during a virtual hearing before a federal magistrate judge in Boston.
Prosecutors allege that Obrezko, who they say previously worked for Russia’s FSB intelligence agency, conspired to commit computer fraud and abuse. The indictment details a cyber espionage campaign, tracked by cybersecurity researchers as “Void Blizzard” and “Laundry Bear,” which aimed to extract data from targeted systems. These operations are also linked to Russia’s invasion of Ukraine, with organizations supporting Ukraine’s resistance being among the targets.
Obrezko faces a maximum of 10 years in prison if convicted. His lawyer stated that they intend to contest the charges vigorously on both factual and legal grounds.
According to court documents, Obrezko worked for the FSB, Russia's domestic intelligence agency, from 2012 to 2017. He then joined the technology firm Yutek-NN, where he served as a deputy director. The indictment asserts that Yutek-NN conducted cyber espionage campaigns at the direction of the Russian government.
Since at least 2023, Obrezko and other associates of Yutek-NN are alleged to have conspired to steal email and other data from company systems. They purportedly used tools such as fake domain names, VPNs, and proxy servers in these efforts. Identified victims include a social media network, a U.S. development company, a cloud software company, and a U.S.-based educational institution. The FBI has identified at least 11 U.S. companies as victims, though they believe the actual number to be higher.
Further details from the indictment indicate that Obrezko’s phone contained a file with AI-generated summaries of over 13,000 stolen emails from members of an Eastern European parliament. Following a May 2025 report by Microsoft detailing the activities of Void Blizzard, Obrezko allegedly communicated with an individual using the alias “Ethan Hunt,” a name referencing a fictional movie character.