Ring of fire / Brad Taylor.

Enhanced descriptions from Syndetics:

Former Delta Force officer and New York Times bestselling author Brad Taylor delivers a relentlessly fast-paced, gripping thriller featuring Taskforce operators Pike Logan and Jennifer Cahill as they come face-to-face with an insidious threat to strike terror into the heart of America.

Fifteen years ago, in order to win a contract in the Kingdom, a desperate defense contractor used a shell company to provide a bribe to a wealthy Saudi businessman. Now a powerful player in the defense industry, he panics when the Panama Papers burst onto the public scene. Providing insight into the illicit deeds of offshore financing, they could prove his undoing.

To prevent the exposure of his illegal activities, he sets in motion a plan to interdict the next leak, but he is not the only one worried about spilled secrets. The data theft has left the Taskforce potentially vulnerable, leaving a trail that could compromise the unit. Back in the good graces of the new president, Pike Logan and Jennifer Cahill are ordered to interdict the next leak as well, in order to control the damage.

Unbeknownst to either group, the Saudi has been using the shell company to fund terrorists all over the world, and he has a spectacular attack planned, coinciding with the fifteenth anniversary of 9/11. The information Pike and Jennifer uncover will put them on the trail of the imminent threat, but it's one that they might be unable to stop.

Called Ring of Fire, it will cause unimaginable destruction across the United States, and the ensuing chaos and terror will distract the Taskforce from a truth no one sees: Ring of Fire was only the beginning, and the danger is far from over.