Hacking is an activity in The Sims 2: University and The Sims 3 that can be performed on a computer.
The Sims 2
"Grade Hacking" is an action available on college computers in The Sims 2: University after a Sim joins a secret society. While hacking, a Sim's class performance will slowly rise, however there is also a risk of getting caught, and that risk generally increases the longer the Sim hacks. Having higher Logic skill reduces, but does not eliminate the chance of getting caught. If a Sim is caught hacking grades, the police will come and fine them, their class performance will be lowered to its original level, and the police officer may pull out a repo-izing gun and confiscate the computer. While hacking, a display in the top-right hand corner of the screen will show the Sim's risk level and the number of security alerts that have been tripped, which allow the player to estimate the chance of being caught. Closing this display will end the hacking session. Players should note that this display may be lost if they switch away from the hacking Sim.
The Sims 3
Sims with the Computer Whiz trait or in the Investigator profession can hack in The Sims 3. Hacking is only possible between 9 pm and 7 am. Depending on the number of times a Sim has hacked before, a set amount of money is put into the household funds every 15–60 minutes (depending on quality/price of computer used). The amount of money the Sim gets depends on how accomplished a hacker he/she is. A high level hacker can earn 4000 simoleons a night and more. Hacking is a hidden skill, so the only way the skill gaining is shown is by the amount of money coming in, there is nothing about it in the skill journal. There is a chance of the police sending a virus to the Sim's computer and breaking it. If this happens and the Sim repairs the computer and keeps hacking, another virus is likely to be sent.