But the Edge Browser hasn't been officially released yet. Hence, flaws and security issues are expected - it's part of the testing-improvement-further-testing loop under the preview version. If Microsoft determines that there is a need for such Windows Defender in Windows Phones, I'm sure they'll release it pre-installed, yet how that'll will work given the sand boxing environment is unclear - perhaps they'll just integrate it into the Smart Screen feature or the default security features of the browser itself as opposed to being a completely separate app.
I believe, however, that the first line of defense against malware and adware is knowing when, where and what to and not to click... or tap.:smile: