thursday detailing how the u.s. believes russia hacked u.s. e-mails. listen. >> we are also disclosing today and exposing today a set of information from the department of homeland security and the fbi that will enable network defenders people operating networks across our country and frashlly internationally to better defend themselves. we are exposing the tactics, the techniques, the procedures that the russian intelligence services have used to interfere in our election and to probe our systems. >> there are people asking where are the facts? show us what is happening. they are showing what's happening. that was lisa monaco, the white house's top homeland security adviser. >> brian todd has more on how the u.s. says russia breached u.s. e-mail systems. >> reporter: moscow says the hacking allegations against russia are groundless. vladimir putin challenging america to prove them. u.s. officials tell cnn the hacks continue around the clock,