Hmmm. The Russians and Chinese don't go advertising their cyberwarfare exploits, but we know of them because targets will be vocal. Our targets would be vocal too. So, I don't think we're doing as much as the other guys in terms of causing random havoc. We generally do "surgical" tits for their tats, as far as I understand. You don't hear Sinopec going off-line or GazProm.
All my searches are only turning up the most recent news about the most recent pipeline hack, but I seem to recall reading that the US hacked/sabotaged an eastern European oil or gas pipeline decades ago.