Cyberattack on US pipeline carried out by criminal gang, says FBI DarkSide, a group of veteran cybercriminals, is believed to be behind the ransomware attack on Colonial Pipeline, the worst cyberattack on critical US infrastructure to date. Colonial Pipeline operates a more than 5,500-mile (8,850 km) pipeline network stretching from Texas to New Jersey. The hackers behind the ransomware attack on a vital US pipeline operator are suspected to be a professional cybercriminal group called DarkSide, the FBI confirmed on Monday. The cyberattack forced Georgia-based Colonial Pipeline to shut a critical fuel network that serves populous states on the East Coast.