washington bill hillary clinton charitable foundation hire security firm fireeye examine data systems see indications might hack accord two source familiar matter far message document hack new york-based clinton foundation surface public source say one source two u.s. security officials say like hackers target democratic national committee hillary clinton presidential campaign democrats congressional fundraise committee hackers appear use spear phishing techniques gain access foundation network elsewhere news u.s. swimmers try return rio yank flight desperate country crush 2,000 gun public plan bullet registry techniques include create bogus email websites effort gain access clinton foundation staffers email foundation speak condition anonymity u.s. officials say hackers use techniques russian intelligence agencies proxies employ democratic party group suggest russians also attack foundation kremlin officials dismiss absurd allegations moscow involvement make last month amid political party nominate conventions nov. election neither former white house counsel kathryn ruemmler clinton foundation principal lawyer spokeswoman foundation respond request comment hack precautions organization take officials fireeye say company could discuss clients although document emerge attack leave democrats clinton campaign officials worry hackers might obtain email voice message could use reinforce republican charge donors clinton foundation reward access clinton aid secretary state husband former president bill clinton another concern hackers outlets anti-secrecy wikileaks website could release document email damage presidential campaign several people familiar foundation activities say democratic congressional campaign committee convene closed-door meet wednesday discuss best cyber security practice meet accord people familiar include recommendation staff lawmakers change phone number email address information publish online hackers believe work russian intelligence agencies one u.s. officials say however spear phishing pattern use several organizations appear reinforce intelligence community preliminary assessment attack intend espionage try influence u.s. presidential election far say third u.s. official familiar attack evidence hackers able follow hack email state department classify email systems anxiety washington possibility foreign power might use hack information meddle u.s. election prompt democrats cyber security experts urge obama administration blame russia publicly rep. jim himes democrat house representatives intelligence committee say unite state carry big stick cyber security matter u.s. government need clear direct hold people accountable current former white house intelligence officials say obama administration unlikely blame russia publicly give difficulty attribute attack without reveal american source methods geopolitical concern play fear could risk aggravate cyber conflict clinton foundation hire cyber firm suspect hack source