Reply #12: Even IF this story is true, there's have to be insider knowledge to do much [View All]

[groundloop]

I've worked with PLC's for years, I'm what you might call an expert. Maybe, just maybe a worm could be written to infect a PLC as claimed. But even after that, you'd have to know the I/O address of each piece of equpment controlled by the PLC to actually do anything. Someone would either need access to the PLC program itself, or at least electrical drawings showing the I/O addresses to really do much.

Having said all that, it is possible a worm could just go in and crash the PLC, in which case the processor card would be removed and a new processor put in it's place (which was sitting on the shelf and likely not infected).

I just really can't see this worm being much of a threat without some serious insider information.