Colonial Hackers Stole Data Thursday Ahead of Shutdown (1)

The hackers who caused Colonial Pipeline to shut down the biggest U.S. gasoline pipeline on Friday began their blitz against the company a day earlier, stealing a large amount of data before locking computers with ransomware and demanding payment, according to people familiar with the matter.

The intruders, who are part of a cybercrime gang called DarkSide, took nearly 100 gigabytes of data out of the Alpharetta, Georgia-based company’s network in just two hours on Thursday, two people involved in Colonial’s investigation said.

The move was part of a double-extortion scheme that is one of the group’s hallmarks. Colonial was ...