The most renown spec ops squad of Russian Imperial Army "The Centuria of Wolves" was lead by yesaul A.G. Shkuro. The conditions of WW1 positional warfare had diminished the role of cavalry, leaving many cavalry detachments in the rear. In the meantime, the idea of mobile special force detachments focused on sabotage missions and lightning attacks in the enemy rear was born. By the end of 1915 Shkuro established "Kuban Mounted Special Forces Detachment". During their first raid in the German rear they destroyed an entire company and captured several dozen PoW, while losing only two personnel. Later Shkuro experienced all the "pleasures" of revolution: ranging from arrests to attempted recruitment to the revolutionary forces. This lead him to the path of resistance. After joining the Volunteer Army*, Shkuro reported to the high command that he doesn't want to lead Stavropol garrison because he's "not trained for defensive action". High command agreed to his proposal to transfer him to Batalpashinsk to lead another uprising. From that moment he became the commander of "the Separate Kuban Guerilla Brigade".
* https://en.wikipedia.org/wiki/Volunteer_ArmyThe Centuria of Wolves