Grace is working on her computer for how to protect herself against computer viruses, and she has learned to not click anything that seems too good to be true because it normally is and will cause a virus to enter your computer
Then she hears a knock at the front door, and heads to check it out.
To her surprise it was a present
She brings the present back to her desk and opens it, it is a flash drive
Not knowing weather to plug it into her computer or not, she does anyway and pictures of random things come up.
However, the flash drive really installed a trojan virus into her computer, and makes her computer crash because trojan viruses cannot self replicate, they Can delete, block, modify, and copy data, and they can disrupt the performance of the computer