Is my device infected/hacked? Today on a normal navigation with firefox a fake popup said 

"your firefox is infected with 2 virus"

then android ask me to give to firefox the "vibration access" of course i refuse.
And then firefox ask me to going to google-play to download antivirus.

I deinstall firefox and reinstall..and the page with advice disappear.

I download then the "free antivirus" from google-play(not the antivirus wich firefox want to force me to download) and do a scan..no virus found.

But now with linux I do a nmap on android device..and port 554(rstp) tcp
is open!
Why is open?Is my device infected or what else?
Solution found,there is something strange on my net because i see 554 port on every machine!

But if i did a telnet outside this machine..554 doesn't answer.

I investigate..meanwhile i'm happy my android is not infected,firefox probably take a fake virus.