They tried to entrap low level people.
They were using numbers of illegal tactics to try and entrap members of the campaign. John Kerry and John Mccain also aided the coup attempt.
“The notion of fully embedded government operatives inside a campaign is hard to imagine under these circumstances,” said Frank Figliuzzi, a former head of FBI counterintelligence and an NBC News national security analyst. “What is easier to imagine is the FBI trying to flesh out information on Russian intelligence operatives by making approaches to campaign staffers if the reasonable suspicion was there and the approvals were in place.”
This is what Stefan Halper was trying to do with Carter Page when Halper approached Page at a conference in the UK. Halper, in this role, would have been an “informant” rather than an embedded “spy,” a technical distinction that has no practical importance in this context.