WASHINGTON — Earlier this week, an anonymous hackers’ group said it would declare war on ISIS, the extremist group said to be responsible for last week’s attack in Paris. It’s an unconventional move that could work, given the hackers’ broad reach and expertise, experts say.

And while ISIS is being hunted by U.S. and international authorities, the hacker group “may also accomplish something,” cybersecurity adviser David Gewirtz told WTOP on Wednesday.

The anonymous group consists of several people with varied skills, who are “taking that fight out into the field regardless of whether governments are supporting it or not,” Gewirtz said. “They may have an impact on people who have already become our enemies.”

Also this week, Gewirtz told CBS News that the cyberattacks can work.

“More to the point, they can go after both the money that terrorists have and their funding sources. Damaging the money flow can certainly have an impact on the terrorists’ operations.”

Anonymous said it would “unleash waves of attacks” on ISIS. On YouTube, a masked activist told the Islamic State that “war is declared.”

“Get prepared,” the person said. “Anonymous from all over the world will hunt you down.”

ISIS uses technology to recruit members. The group even has a help desk for members who need help with their computers. So far, Gewirtz said, Anonymous has knocked out more than 3,800 pro-ISIS Twitter accounts, which the group uses to recruit new members and disseminate propaganda.

So far, Anonymous has attacked the websites of companies and government agencies that disrupt flows of information.

“If this vigilante group can impact that, even though they’re doing things that are kind of illegal, you have to cheer for them at the same time,” Gewirtz said.