hack into

No — say "They hacked into the system.". the preposition 'into' is necessary to indicate the movement or entry into the digital space.

Definition

phrasal verb. to gain illegal access to a computer system or a private account by breaking through security.

phrasal verb. to gain unauthorized access to a computer system, network, or digital account, typically by circumventing security protocols.

simple

“Someone tried to hack into my email account last night.”

contextual

“The company's database was compromised after a group of teenagers managed to hack into their main server.”

complex

“Cybersecurity experts warned that foreign agents were attempting to hack into the national power grid to disrupt essential services.”

always followed by the object being accessed, such as a computer, account, or network.

contrast with 'hack' (intransitive or general) and 'break into' (physical or digital); 'hack into' specifically emphasizes the digital entry point.

They hacked in the system.

They hacked into the system.

the preposition 'into' is necessary to indicate the movement or entry into the digital space.

Particles

into

Separability

inseparable

Pattern

hack + into + object