According to Poland's PAP news agency, the data acquired by Ukraine’s Centre for Defence Strategies think tank includes the soldiers' names, locations and registration numbers.
The data has been published online by the Ukrainian Pravda news outlet, the PAP news agency reported.
According to the pravda.com.ua website, the Centre for Defence Strategies said it had acquired the data from "reliable sources."
On Monday, the websites of several Russian media outlets were hacked, with their regular sites replaced by an anti-war message and calls to stop President Vladimir Putin's invasion of Ukraine, the Reuters news agency reported.
Source: PAP, pravda.com.ua, Reuters