You must be somebody else's VPN. As it were. There are plenty of uses for pwned machines. Since they are free, the uses don't even need to makes sense.
No, I ran a test through two linux VPSes that I control, and both of them show me downloading something I didn't. I'm reasonably sure that neither of my boxes were compromised, although if we want confirmation we can get someone who works at a hosting company to check with an IP that hasn't been routed in months. I posed a explanation in a sibling comment: https://news.ycombinator.com/item?id=24256890
