hash has been placed on administrative leave pending a state investigation, and the f.b.i. says it is monitoring the situation. norah. >> o'donnell: nancy chen, thanks. all right, stewart rhodes, the founder of the oath keepers, a far-right militia,s made his initial court appearance in plano, texas, today on seditious conspiracy charges related to the january 6 attack on the capitol. a judge ordered him detained pending a hearing on january 20. tonight, u.s. officials are sounding the alarm about a russian ploy designed to give vladimir putin an excuse to invade ukraine. the warning follows a widespread cyberattack on ukrainian government web sites. we get details from cbs' margaret brennan. >> reporter: as russia conducts military exercises on the ukrainian border, u.s. intelligence revealed today that russia has prepositioned operatives trained in urban warfare and explosives to carry out acts of sabotage on its own