Still Getting Paid After Quitting

I’ve been secretly getting paid for a job I quit six months ago, and I don't know

when to stop. I worked for a massive tech corporation that went through a messy restructuring.

I turned in my resignation, my boss signed it, and I moved on. However, every two weeks,

my full salary still hits my bank account. I checked my old employee portal—I’m still listed as

"Active," but I have no login access to do any work. I’ve been putting the money into a

high-yield savings account just in case they ask for it back, but it’s been half

a year and no one has noticed. What would you do?