hijack

/ˈhaɪdʒæk/ verb [T]

Definition

› to take control of something, such as another person's plan, a system, or a meeting for your own advantage: The association is annoyed that its campaign has been hijacked by pin-striped PR men.

› IT to take control of a computer belonging to someone else without their permission, especially for illegal purposes: Hundreds of the department's powerful computers were hijacked by hackers, who used them to send spam email.

(Definition of hijack verb from the Cambridge Business English Dictionary © Cambridge University Press)