System hacking is where the attacker proceeds towards the ultimate goal after performing footprinting, scanning, enumeration, and exploitation. The goal can be to bring the service down and make it un-available or steal data or manipulate data.
The general stages of System Hacking are as following:
Stage 1 – Gaining Access
Stage 2 – Privilege Escalation
Stage 3 – Maintaining Access
Stage 4 – Clearing Logs
Please refer to Cyber Kill Chain to understand the phases of Cyber Security Attack in detailed.