SAME NETWORK BREACH

Good evening,

I made an account here just today but I've been using nullbyte for years now so thank You for all the terrific work and help you keep posting here.

I use kali linux and WIN7 on my main device and my brother uses Mac OSx in which has confidential emails and documents, vital to his business.

At the moment we use our building WIFI that only the residents have the password for.

I'm a mere script-kiddie and Im a keen learner of Pentesting for the sole purpose of protecting myself and family when accessing web facilities.

I noticed that sometimes pages loose the https and I've told my brother to never access confidential info when running on simple http pages.

Now my question is:

is there any way that somebody could hack into my brother's mac to run keyloggers, sniffers, payloads and such ?

I tried with armitage, metasploit and many other tools and the most I could do was sniffing the websites accessed by my brother (using bettercap and bettercap V2 tools on git).

He uses gmail and I've seen it doesnt exist an http version of it so page spoofing is pretty much impossible to me.

I do not define myself an hacker so any IT expert able to answer my questions will be greatly accepted.

Is he safe? if not, how can they hack him ? How can I protect him ?

Thank you in advance for your support.

K.S.

Extra info:

-Wifi password for this network is easily and quickly crackable using any WPS tool;

-Is impossible to access modem/router webpage at 192.168.1.254 but only at the providers website.

-On the page given by the provider there isnt much you can do (just password changing and router channel changing)

-Port Forwarding is also impossible for this network.

-pardon my bad English and thank you very much.