Software that encrypts your entire hard drive, demanding payment to restore your engineering projects and personal files.
If you are a freelancer or professional using a crack at home, your .ms14 circuit files could contain hidden metadata or macros. If you ever share those files with a legitimate client or send them to a PCB manufacturer, you risk infecting their systems. This is a career-ending mistake.
So, what do you do? Give up on learning electronics? Absolutely not. There are fantastic, safe, and often completely free ways to get access to Multisim or equivalent software.