https://www.vice.com/en_us/article/v7djda/ukraine-arrests-hacker-routing-calls-for-russian-troops

The Security Service of Ukraine (SSU) says it has detained a “hacker” who was providing technical assistance to Russian troops in Ukraine by routing phone calls on their behalf, and who also sent text messages to Ukrainian security forces suggesting they surrender. In short, the hacker appeared to be leveraging Ukrainian phone networks to facilitate Russian military communications.

The news provides a look at the sort of technical operations that are underpinning parts of the invasion, and comes as Russian troops have faced multiple issues around communications, including being unable to use their own established secure communications network.