Ukraine has been more deliberate about recruiting a volunteer hacking force. In Telegram channels, participants cheer their collaboration with the government in going after targets such as Sberbank, the Russian state-owned bank. From Russia, where links between the government and hacking groups have long raised alarms among Western officials, there has not been the same kind of overt calls to action.
“We are creating an I.T. army,” Ukraine’s minister of digital transformation, Mykhailo Fedorov, tweeted on Saturday, directing cybersecurity enthusiasts to a Telegram channel that contained instructions for knocking Russian websites offline. “There will be tasks for everyone.” By Friday, the Telegram channel had more than 285,000 subscribers.
Inside the main English-language Telegram page for the I.T. Army of Ukraine is a 14-page introductory document providing details about how people can participate, including what software to download to mask their whereabouts and identity. Every day, new targets are listed, including websites, telecommunications firms, banks and A.T.M. processors.
Yegor Aushev, the co-founder of the Ukrainian cybersecurity company Cyber Unit Technologies, said he was flooded with notes after posting on social media a call for programmers to get involved. His company offered a $100,000 reward for those who identify flaws in the code of Russian cyber targets.
Mr. Aushev said there were more than 1,000 people involved in his effort, working in close collaboration with the government. People were only allowed to join if somebody vouched for them. Organized into small groups, they were aiming to hit high-impact targets like infrastructure and logistics systems important to the Russian military.
“It’s become an independent machine, a distributed international digital army,” Mr. Aushev said. “The biggest hacks against Russia will be soon,” he added, without elaborating.
A government spokesman confirmed the work with Mr. Aushev.
Figuring out who is behind a cyberattack is always difficult. Groups falsely take credit or boast of a bigger impact than actually occurred. But this week there was a string of attacks against Russian targets. The country’s largest stock exchange, a state-controlled bank and the Russian Foreign Ministry were taken offline for a time after being targeted by Ukraine’s volunteer hackers.