UPDATE 1-Ukraine asks FBI for help to probe suspected Russian hack of Burisma

Ukraine has appealed to the Federal Bureau of Investigation (FBI) for help in investigating a suspected cyber attack by Russian military hackers on the energy company Burisma, a Ukrainian interior ministry official said on Thursday.

Burisma Holdings was at the center of attempts by President Donald Trump last July to ask Ukrainian authorities to announce an investigation into Hunter Biden, the son of Democratic U.S. presidential contender Joe Biden. California-based cybersecurity company Area 1 Security on Monday identified the hacking of Burisma and linked it to Russia's Main Directorate of Military Intelligence, or GRU.

The same hacking group, known as "Fancy Bear" or "APT28" by cybersecurity researchers, breached the Democratic National Committee in 2016 in what U.S. investigators described as part of an operation to disrupt that year's election. Russia's defense ministry did not respond to a request for comment about Area 1 Security's assertions.

"It is noted that the hacker attack most likely took place in cooperation with the Russian special services," Ukrainian interior ministry official Artyom Minyailo said at a briefing. Minyailo said Ukraine had asked the FBI and Area 1 Security for assistance.

At the same briefing, the interior ministry also announced a probe into the possible illegal surveillance of the then U.S. ambassador to Kyiv Marie Yovanovitch, following revelations in documents published by the U.S. Congress this week. Hunter Biden used to have a seat on the board of Burisma. There has been no evidence of wrongdoing by the Bidens, who reject Trump's allegations of corruption.