> "But at about 1:30 p.m. the same day, Gualtieri said, someone accessed the system again. This time, he said, the operator watched as someone took control of the mouse, directed it to the software that controls water treatment, worked inside it for three to five minutes and increased the amount of sodium hydroxide from 100 parts per million to 11,100 parts per million."

who wants to bet this might have been as simple as improper usage/implementation of Teamviewer gone wrong?

when dealing with persons/organizations who are not focused on infosec/netsec issues, given the opportunity and ability to do so, never underestimate the workarounds and kludges that people will install to "make their job easier", such as putting teamviewer on control system PCs running water systems.