A top Ukrainian official says a Belarusian intelligence agency is likely behind the hacking of several Ukrainian government websites this week.
Serhiy Demedyuk, deputy secretary of Ukraine's national security and defense council, spoke with Reuters on January 15, a day after Ukrainian websites were disabled and defaced with threatening messages.
Demedyuk said a group known as UNC1151 was behind the hack.
"This is a cyberespionage group affiliated with the special services of the Republic of Belarus," he said in a written comment to Reuters.
The cyberattack came as Russia has massed tens of thousands of troops near Ukraine's borders. The crisis, and the threat of a new invasion of Ukraine, brought diplomats from Washington, Moscow, and Europe together for three separate, high-level meetings this past week.
Ukrainian and other officials have also suggested that Russia was likely involved in the hack, but provided no proof.
Belarus is a close ally of Russia, which has dismissed such fears as "unfounded."
Belarusian officials did not respond to a request for comment.
"The group specializes in cyberespionage, which is associated with the Russian special services and which, for its attacks, resorts to recruiting or undercover work of its insiders in the right company," Demedyuk told Reuters.
The group UNC1151 has been tracked by cyberexperts in the past.
In November, the private company Mandiant published a report alleging UNC1151 was behind a campaign to steal government credentials and spread disinformation in Europe. Mandiant said it had "moderate confidence" that Belarus was "at least partially responsible" for the campaign known as Ghostwriter.
"We cannot rule out Russian contributions to either UNC1151 or Ghostwriter," Mandiant said.