washington fbi investigate suspect attempt hack mobile phone use democratic party officials recently past month four people direct knowledge attack investigation tell reuters revelation underscore widen scope u.s. criminal inquiry cyber attack democratic party organizations include presidential campaign candidate former u.s. secretary state hillary clinton u.s. officials say believe attack orchestrate hackers back russian government possibly disrupt nov. election clinton face republican party candidate donald trump russia dismiss allegations involve cyber attack organizations recent attempt phone hack also appear conduct russian-backed hackers two people knowledge situation say federal bureau investigation representatives immediate comment clinton campaign spokesman say unaware suspect phone hack democratic national committee dnc respond request comment official democratic congressional campaign committee dccc say nobody organization contact investigators possible phone hack interim dnc chairwoman donna brazile tell cnn struggle russian hackers announce june ongoing know would choose provide general update unless personal data sensitive information access steal fbi agents approach small number democratic party officials discuss concern mobile phone may compromise hackers people involve say clear many people target hack whether include members congress possibility could raise additional security concern u.s. officials successful hackers could able acquire wide range data target cellphones include call data text message email photos contact list one person knowledge situation say sense phone office brain say bruce schneier cyber security expert resilient ibm company involve investigation incredibly intimate anything phone phone hack hacker get it fbi ask whose phone believe hack turn phone investigators could image create copy device relate data u.s. investigators look whether hackers use data steal servers run democratic organizations private email employees get access cellphones one person say hackers previously target servers use dnc body set strategy party dccc raise money democrats run seat house representatives officials say clinton say monday presidential debate doubt russia sponsor hack kinds organizations country mention russian president vladimir putin name putin play really tough long game one things do let loose cyber attackers hack government file hack personal file hack democratic national committee clinton say trump counter definitive proof russia sponsor hack democratic organizations think anybody know russia break dnc say could russia could also china could also lot people fbi probe hack target phone democratic party officials source