It's mostly not infected computers, but rather poorly configured proxies that are open for anyone to bounce malicious traffic through. Convincing everyone to clean up their open proxies is a long-term, hard problem. But I plan to tackle it soon....

How? I suppose the most effective way is to have those proxies attack each other. But don’t, it’s likely illegal.

the most efficient way would be to write a script that gains root on those open proxies and then fixes the issue.

Effective or efficient? Would seem rather inefficient to spend time researching all the possible ways to gain route on x number of servers, finding an exploit, crafting some plan to execute it, keeping your prints clean etc etc

What way would be more efficient?

Get a few companies to agree that open proxies are a scourge that needs to be stopped. They each apply some action to open proxies (user-facing messaging, loss of functionality, captcha, or complete block), and the users of those proxies will get the problem fixed.

The hard part (and it truly is hard!) is convincing a few companies to do this. It risks user complaints in the short term, to solve a problem that may not be very acute for the largest companies (who can simply absorb these attacks).

[delayed]