washington hackers believe work russian government break democratic national committee computer network spy internal communications access research presumptive republican presidential nominee donald trump committee security experts say tuesday two separate group enter dnc system one read email chat communications nearly year detect accord committee crowdstrike cyber firm help clean breach russian spy also target network trump democratic presidential candidate hillary clinton well computers republican political action committees washington post quote u.s. officials say although detail available clinton campaign official say evidence campaign information systems hack russian government spokesman deny involvement breach completely rule possibility russian government government body involve dmitry peskov kremlin spokesman tell reuters moscow intrusion emblematic sophistication russian hackers intelligence officials long view talented u.s. adversaries cyberspace democratic party aware efforts hack trump material two months u.s. intelligence agencies involve efforts find behind hack source familiar trump opposition research say source say democratic party operatives believe hack conduct russian government research include material trump business efforts azerbaijan georgia serbia russia accord information make available reuters cyber attack political candidates organizations common worldwide u.s. national intelligence director jam clapper say last month aware attempt hack campaign relate group expect see nov. presidential election near u.s. representative jim langevin democrat co-founder congressional cybersecurity caucus say disconcert independent group penetrate dnc one able stay embed nearly year group extremely sophisticate langevin say previously implicate attack white house state department german bundestag well number private company dnc contact crowdstrike may within 24 hours begin investigate unusual activity group network say dmitri alperovitch company co-founder chief technology officer identify two hack group kick weekend say first crowdstrike name cozy bear enter dnc systems last summer accord firm primarily monitor email chat conversations may work russia federal security service fsb alperovitch say russian president vladimir putin run fsb second group nickname fancy bear probably work behalf russia military alperovitch say gain entry late april go straight oppo research ... donald trump exfiltrated say alperovitch say group among best threat actors ever encounter appear work together sure intrusions occur suspect hackers may leverage spearphishing email trick dnc employees download malicious code onto network discover intrusion treat like serious incident rep. debbie wasserman schultz chairwoman dnc say statement team move quickly possible kick intruders secure network trump interest russia go back 1980s 1990 vanity fair article cite news program appearances trump offer service negotiator russia information make available reuters indicate trump try least three occasion 2004 2008 2013 get involve business deal russia 2013 azerbaijani-russian oligarch aras agalarov jointly put miss universe competition moscow trump photograph agalarov wife son daughter last two u.s. presidential cycle 2008 2012 witness barrage cyber attack range adversaries target president barack obama campaign campaign republican foes u.s. intelligence officials say many previous assault link chinese hackers russians steal research trump hack u.s. democratic party