The reaction you describe matches the profile of an electrophilic aromatic substitution. If I'd have to guess what compound
The nitration of benzene refers to the introduction of a nitro group into benzene by way of a nitrating mixture. Here is where the nitric acid and the sulfuric acid, which acts as a catalyst, come into play.
The first step in the nitration of benzene is the creation of the nitronium ion,
Since it is the stronger acid, sulfuric acid will protonate nitric acid on the
The electron-rich benzene ring will attack the strong electrophile nitronium ion to eventually form nitrobenzene and sulfuric acid