U.S. investigators have recovered millions of dollars in cryptocurrency paid as a ransom to the cybercrime group responsible for the attack that shut down Colonial Pipeline last month, the Justice Department announced Monday.

Driving the news: Colonial Pipeline CEO Joseph Blount told the Wall Street Journal he authorized a ransom payment of $4.4 million to the DarkSide cybercrime group on May 7th, in an attempt to restore service of the largest refined fuel pipeline in the U.S.

• The company, however, had notified the FBI and followed instructions to help U.S. investigators track the payment, CNN reported.
• The federal government has for years recommended that companies do not pay those responsible for ransomware attacks due to fears that the transactions would encourage more groups to conduct future attacks.

The big picture: The attack caused gas stations in least 12 states and the District of Columbia to experience gas shortages.

What they're saying: "Ransomware attacks are always unacceptable, but when they target critical infrastructure, we will spare no effort in our response," said Deputy Attorney General Lisa Monaco.