Properly protecting industrial environments is a relevant activity in the network security field, due to the significant impact that potential cyberattacks may have. By exploiting the possibility of designing new threats targeting industrial networks, in this paper we present SlowROS, a novel Slow DoS Attack targeting the Robot Operating System, ROS. In our work, we validated the threat through the execution of dedicated test sets on a real network, composed of multiple interacting components. Obtained results show that the proposed attack leads to a denial of service against ROS components, making them unable to operate correctly. Indeed, although we did not directly targeted it, we also observed the attack impact on a typical ROS device and discussed how a production pipeline can be blocked by SlowROS. In addition, we found non-negligible peaks of data exchanged, thus we discussed how it is possible to optimize the threat and minimize its impact on the network in terms of network bandwidth needed by the attacker, by exploiting the potentially endless connection timeout of the targeted service.