The IT Army of Ukraine was born in the opening days of the Russian invasion of Ukraine. It started with a simple tweet on Feb. 26, 2022 from Mykhailo Fedorov, vice prime minister and minister of digital transformation, who wrote, “We are creating an IT army. We need digital talents” and included a link to a Telegram channel where visitors could find a list of targets to attack. The concept behind the group is simple: The operators of the channel provide tools to conduct distributed denial of service (DDoS) attacks against Russian websites and put out a list of targets two or three times per week for volunteers to attack. These volunteers then use the tools from the channel and, in some cases, their own hacking skills, to take down services on the Russian internet, including banking websites, tax processors, and military hardware stores. The group has attacked prominent Russian websites and even managed to delay Vladimir Putin’s speech at the St. Petersburg Economic Forum for over an hour.
Above from the very recent Lawfare Blog article
More info - doing a bit of study on the IT Army of Ukraine today as I hadn't heard of much activity from them in recent months.
IT Army of Ukraine website: https://itarmy.com.ua/?lang=en
Their Telegram channel: https://t.me/itarmyofukraine2022
English version: https://t.me/itarmyofukraine2022eng
Wikipedia: https://en.wikipedia.org/wiki/IT_Army_of_Ukraine