In a Facebook post on Tuesday, Ukrainian officials said that a denial-of-service cyberattack had targeted the country's Ministry of Defense and its armed forces.
The cyberattacks were also targeted at two of Ukraine's largest banks, Privat and Oshchadbank.
Denial of service attacks occurs when a malicious actor shuts down a computer network by flooding it with traffic or repeatedly sending information to a server that triggers a slow response or a crash.
The cyberattacks come as Russia has amassed more than 100,000 troops at Ukraine's eastern border. Russian President Vladimir Putin has denied that he intends to attack, but U.S. officials believe Russia has enough military assets in a position where an invasion could happen "at any time."
On Tuesday, Putin said he would keep dialogues open with the U.S. and NATO about security improvements in the region, sparking hope of a peaceful resolution.