‘Most Wanted’ Man Pleads Guilty in Cyberattack That Upended Vermont Hospital

A Ukrainian man pleaded guilty in federal court on Thursday to his leadership role in two cyberattack schemes that caused tens of millions of dollars in losses and temporarily crippled a Vermont hospital in 2020, according to the Justice Department.

Prosecutors said that Vyacheslav Igorevich Penchukov, 37, was a leader for an organization that in May 2009 began to infect thousands of computers at corporations with malicious software, and that he helped lead a separate malware scheme that began around November 2018.

Mr. Penchukov, of Donetsk, pleaded guilty in the U.S. District Court in Nebraska to one count of conspiracy to commit an offense that violated the Racketeer Influenced and Corrupt Organizations Act and one count of conspiracy to commit wire fraud. He was arrested in Switzerland in 2022 and was extradited to the United States in 2023. A lawyer for Mr. Penchukov could not be found because the court file was sealed.

The Justice Department said that Mr. Penchukov helped lead “a wide-ranging racketeering enterprise and conspiracy” that installed malicious software known as Zeus onto thousands of business computers, starting in 2009. The malware allowed the enterprise to collect information used to log into online banking accounts, including passwords and personal identification numbers.

Mr. Penchukov and other members of the group then portrayed themselves as employees of the corporations who were authorized to transfer money from the accounts they targeted, causing millions of dollars in losses, according to the Justice Department.

The money was deposited into the accounts of residents of the United States and other countries who were known as “money mules,” and those people then sent it to overseas accounts that were run by Mr. Penchukov and other members of the group, according to the Justice Department.

Mr. Penchukov had been charged for these offenses in 2012 while he was still at large, according to an indictment that was unsealed in 2014.

On Thursday, Mr. Penchukov also pleaded guilty to his leadership role in the separate malware scheme that ran from at least November 2018 to February 2021, according to federal prosecutors.

The malware, known as IcedID or Bokbot, was installed on computers to collect personal information from victims, including bank account credentials, and the data was used to steal from them, according to the Justice Department. IcedID also allowed the cybercriminals to install more malware on infected computers, including ransomware, which is used to lock digital information until the victim pays for its release.

The targets of these ransomware attacks included the University of Vermont Medical Center, which lost more than $30 million, according to the Justice Department. A 2020 attack on the hospital also “left the medical center unable to provide many critical patient services for over two weeks, creating a risk of death or serious bodily injury to patients,” the Justice Department said.

Workers at the University of Vermont Medical Center told The New York Times in November 2020 that the attack had forced the hospital to send away hundreds of cancer patients and required staff to search through written records to find important information.

In September 2023, the medical center’s president, Dr. Stephen Leffler, testified in the House of Representatives, and said that the hospital did not have access to electronic medical records for 28 days because of the attack.

“We didn’t have internet,” Dr. Leffler said. “We didn’t have phones. It impacted radiology imaging, laboratory results.”

The hospital said in a statement that it was “proud of our team’s work to provide the best possible care while the investigation and restoration were underway.”

Mr. Penchukov was also known as Vyacheslav Igoravich Andreev and Tank, an online nickname, according to the Justice Department. He had been on the F.B.I.’s Cyber’s Most Wanted List for nearly a decade.

Mr. Penchukov’s sentencing is scheduled for May 9. He faces up to 20 years in prison for each count.