https://www.theregister.co.uk/2018/02/01/adobe_flash_security_patch/

Adobe will next week emit patches to squash a security bug in Flash that can be exploited by malicious webpages and documents, when opened, to hijack and spy on vulnerable computers.

The flaw is being abused right now by North Korean hackers to infect victims' PCs. You should update your browser or Flash installation – if you're still using Flash – as soon as the fix lands so other miscreants can't exploit the vulnerability and potentially commandeer your machine.