The House Oversight and Homeland Security committees said Monday that they remain “extremely concerned” following a briefing with Colonial Pipeline, a major fossil fuel company that fell victim to a ransomware attack that caused a gas shortage in several states.

In a joint statement, House Oversight Chair Carolyn Maloney (D-N.Y.) and House Homeland Security Chair Bennie Thompson (D-Miss.) said it was “deeply troubling that cyber criminals were able to use a ransomware attack to disrupt gas supply on the East Coast and reportedly extort millions of dollars.”