The development follows speculation and concern among security experts that the attack group would expand its scope to the power grid.   The attackers behind the epic Triton/Trisis attack that in 2017 targeted and shut down a physical safety instrumentation system at a petrochemical plant in Saudi Arabia now have been discovered probing the networks of dozens of US and Asia-Pacific electric utilities. Industrial-control system (ICS) security firm Dragos, which calls the attack group XENOTIME, says the attackers actually began scanning electric utility networks in the US and Asia-Pacific regions in late 2018 using similar tools and methods the attackers have used…