Leanne Zaloumis, 29, thought to be an overzealous fan, was subdued by the X Factor judge’s on-site security team, Reuters reports. She was later charged with trespassing on the property and intending to “inflict grievous bodily harm upon a person therein.”
Cowell spokesman Max Clifford told the Sun that his client heard a loud bang and rushed upstairs to investigate.
“It came from the bathroom, so he went in – and there was a woman standing there holding a brick,” Clifford said. “She had smashed her way in through the window, and it was unclear how long she had been there or what she was doing.”
Clifford added: “It was a very frightening experience for Simon, who told me it was like something from a horror movie.”
A rep for Cowell declined to comment to PEOPLE, but it is officially now a police matter.