Course it's still alive.

We sadly do not yet posses an antivirus system that sends the equivalent of a blast of fire through the entire internet to "cleanse" it from a threat.

The WannaCry worm, just as most worms who've ever been created, can spread independently of their authors. as long as there are computer's in existence that isn't patched, they'll be potential hiding places for worms.

It's kind of like SIDA. The disease is so hard to kill because even if we send something through the entire body to kill the free virii, some are in places our immune system can't reach. So as soon as we're not actively chasing it, it'll emerge and re-attack vulnerable cells again.

I seem to remember some researchers at some point mentioning potentially spreading immunity to a computer virus or worm through "viral updates". Basically, if you're connected, a "security worm" would inspect your system using some special entrance made just for it and update to the latest version every single piece of software it knew was vulnerable..

I think the idea was scrapped pretty fast, as other worms could discover the entrance, and a lot of infrastructure today depends on the program using that specific version of a framework or tool, and upgrading could break an entire system unless it's recoded.