"This release includes bug fixes, increased stability and performance improvements." The routine software update may be one of the most familiar and least understood parts of our digital lives. A pop-up window announces its arrival and all that is required of us is to plug everything in before bed. The next morning, rather like the shoemaker and the elves, our software is magically transformed. Last spring, a Texas-based company called SolarWinds made one such software update available to its customers. It was supposed to provide the regular fare — bug fixes, performance enhancements — to the company's popular network management...