If you have to ask, lone wolf behavior is more likely to end up with you in jail than to do anything that helps Ukraine. If you are serious and are a citizen of a signatory to NATO, consider enlisting with your country's cyber force.
> "Ukrainian cybercommunity! It's time to get involved in the cyber defense of our country," the post read, asking hackers and cybersecurity experts to submit an application via Google docs, listing their specialties, such as malware development, and professional references.
As long as you're in a country where it's not illegal to help the Ukraine, I say put in an app and see where it goes :-)
[1]: https://en.wikipedia.org/wiki/United_States_Cyber_Command#Op...
> Only if you’re an amateur