I think it is highly unlikely that spacex or anyone else disassembles and reverse engineers the satellites they are paid to launch.
Maybe they look for a reentry shield and radioactive emissions or something, but I don't think it is much of a risk since the blowback from trying to sneak a weapon into space would immense, the risk of discovery is high (satellites weight much less than nukes or kinetic weapons) and you will have just given the world community all the evidence it needs to prove you did it (nuclear weapons and satelite payloads are very traceable).
Of course someone could get a satellite launched that maybe has enough fuel to change orbits slightly and could be used as a weapon against the space station or other orbital assets. The difference between a satellite and an orbital missile is software and maybe a small delta in fuel.
Maybe they look for a reentry shield and radioactive emissions or something, but I don't think it is much of a risk since the blowback from trying to sneak a weapon into space would immense, the risk of discovery is high (satellites weight much less than nukes or kinetic weapons) and you will have just given the world community all the evidence it needs to prove you did it (nuclear weapons and satelite payloads are very traceable).
Of course someone could get a satellite launched that maybe has enough fuel to change orbits slightly and could be used as a weapon against the space station or other orbital assets. The difference between a satellite and an orbital missile is software and maybe a small delta in fuel.