A total of 3,000 cyber attacks against Ukrainian targets have been recorded since mid-February, according to Victor Zhora, the deputy chairman of the country's SSSCIP cyber security agency.
Many of the attacks, almost certainly from Russia, have been aimed at knocking out internet service providers and other communications as well as government and financial services in parallel with Moscow's military offensive, Zhora added.
The record number was "275 in a day" Zhora told reporters in a briefing, part of an uptick in hacker attacks seen since before the war started on 15th February.
Most were denial of service attacks aimed at preventing a service from functioning.
An apparent attack on Viasat, a satellite communications company, at the end of February that disrupted service in Ukraine and elsewhere is under investigation by Ukraine, Zhora said, as well as reportedly by the US National Security Agency.
Some of Russia's traditional military activity has also been aimed at disrupting communications, Zhora added, including the bombing of TV towers in Kyiv a fortnight ago and in Rivne, in the north of the country, on Monday.
Mobile communications have also been affected, at times, most recently in the southern city of Kherson, as Russian forces destroy base stations.
It was part of a concerted effort to prevent Ukrainians from communicating and removing their sources for information, the official said.
"They will use all the means they can to change the infosphere in Ukraine," Zhora added.