This sentence uses the passive voice. The structure is [Noun A] に [Verb (passive form)]。It means that Noun A is the agent who performs the action, and the speaker (or the subject of the sentence) receives that action. It often implies a situation where something is done to you, sometimes without your will.

誰かから動作を「される」受身形です。動作主を「〜に」で表します。