NBC's sources didn't mention anything specific, but the intelligence agency apparently already possesses a collection of documents that could expose Putin's "unsavory tactics." While we can only guess what those documents contain, Vice President Joe Biden recently dropped a hint: "It's well known that there's great deal of offshore money moved outside of Russia from oligarchs," he said. "It would be very embarrassing if that was revealed..."
A couple of CIA officers told NBC News that the White House worked with the agency to wage cyberwar against Russia several times in the past. However, the government would always drop the idea, because anything the US can do, Putin and his cohorts can, as well. "Do you want to have Barack Obama bouncing checks?" one of the agents asked. Ultimately, it's up to the president to decide whether to push through with a covert operation or to retaliate against the Russian government with something more visible, like imposing sanctions.
Since the cat's now out of the bag and the White House's plans aren't so secret anymore, though, some people (like WikiLeaks) are doubting whether the government is actually serious, or if this is merely a political ploy.
If the US "clandestine" pending cyberwar on Russia was serious:
— WikiLeaks (@wikileaks) October 15, 2016
1) it would not have been announced
2) it would be the NSA and not the CIA