Sabotage the control system so that it blows up instead. There are a couple of previous claimed cyberwarfare attacks on pipelines that resulted in pipelines blowing up (e.g., https://en.wikipedia.org/wiki/At_the_Abyss, although that's one that I do not believe to be true).
Interesting, thank you.
TL;DR
> "The pipeline software that was to run the pumps, turbines and valves was programmed to go haywire, to reset pump speeds and valve settings to produce pressures far beyond those acceptable to the pipeline joints and welds. The result was the most monumental non-nuclear explosion and fire ever seen from space."
How can cyberwarfare blast something some km close to an underwater gas pipe? remote controlled submarine?