An unknown webpage opens while using my samsung galaxy A9

[AC Question]

Sometimes while using my samsung galaxy A9 an unknown page opens leading me to a porn page or gets answer these questions and win apple7 , its v.v irritating
I tried all ur solutions of comments but it didn't work ....
Now please tell me what to do

 

[jasonandrews25788]

if this happens only with one browser try to clear the cache & data of this browser.