Kompromat, short for "compromising material" in the Russian culture, is damaging information about someone which can be used to blackmail, extort, or put them away. Kompromat can be legitimate, acquerid through security services like spying on someone, or it could be completely forged and used for purely political reasons of getting someone out of the way and putting them in prison or even executing them.
Early on in this practice it used to be planted drugs, grainy videos of prostitutes hired by the KGB, and other entrapment techniques. More recently kompromat appears in the form of cybercrime. The information in either case is often sexual in nature, such as when a civil servant was the victim of a gay honey trap during a time in Britain when homosexuality was against the law.
Some enemies of Russia say the government plants child porn on them. What a tactic, what a world.