Two Las Vegas casinos’ networks were down over the past week, with posted signs saying “Cash Only” throughout the casinos after a suspected ransomware attack. Electronic slot machines were silent as the casinos reacted to the security incident.

The Nevada State Gaming Control Board was aware of the situation and disclosed that it is monitoring the incident.

It is being reported that the intrusion into the casinos’ systems allegedly affected “slot machines, player loyalty programs, credit card processing, hotel reservations, and ATMs.”