Andres Sepulveda tells Bloomberg he rigged major political campaigns over a period of eight years in Nicaragua, Panama, Honduras, El Salvador, Colombia, Mexico, Costa Rica, Guatemala, and Venezuela.

“With a budget of $600,000, the Peña Nieto job was by far his most complex. He led a team of hackers that stole campaign strategies, manipulated social media to create false waves of enthusiasm and derision, and installed spyware in opposition offices, all to help Peña Nieto, a right-of-center candidate, eke out a victory.”

Now serving 10 years in prison in Colombia, Sepulveda is telling his story in hopes of a reduced sentence.

On the question of whether the U.S. presidential campaign is being tampered with, he is unequivocal: “I’m 100 percent sure it is.”