RUSSIAN OPERATIVES USED MALWARE ON ANDROID DEVICES TO TRACK AND TARGET UKRAINIAN ARTILLERY: This Reuters report strikes me as well sourced.

The malware was able to retrieve communications and some locational data from infected devices, intelligence that would have likely been used to strike against the artillery in support of pro-Russian separatists fighting in eastern Ukraine, the report from cyber security firm CrowdStrike found…The hacking group, known commonly as Fancy Bear or APT 28, is believed by U.S. intelligence officials to work primarily on behalf of the GRU, Russia’s military intelligence agency.

More:

The implant leveraged a legitimate Android application developed by a Ukrainian artillery officer to process targeting data more quickly, CrowdStrike said.

Its deployment “extends Russian cyber capabilities to the front lines of the battlefield”, the report said, and “could have facilitated anticipatory awareness of Ukrainian artillery force troop movement, thus providing Russian forces with useful strategic planning information”.