"Covert attacks" refers to secret or hidden actions carried out against someone or something, often with the intention of causing harm or damage without being noticed or caught. Full definition
The second trailer has arrived, which finds Moss going undercover to infiltrate an anarchist collective known for executing covert attacks upon major corporations. (movieweb.com)
She is assigned to go undercover to infiltrate an anarchist collective known for executing covert attacks upon major corporations. (movieweb.com)
Having our eyes and hearts opened by the heinous attacks in Paris shouldn't also blind us to the more covert attacks on our civil liberties that may come as a second wave assault. (rabble.ca)