Why is there ads and pop up appearing everywhere?

[Turtle]

So i opened google chrome and when on tumblr and twitter and there were ads where there shouldn't be and i don't know how to hide them or remove them and i don't know why they're appearing. Also sometimes when i click something a pop up would pop up and it shouldn't. Please help
This happened before but somehow got resolved

[Ⓐⓝⓖⓔⓛ]

Ads and pop ups are a clear indication of your system being infected with malware.
Download Superantispyware and AVST. Install and run both. Remove and found threats. Restart computer.

Download AVAST from
http://download.cnet.com/Avast-Free-Anti...ag=mncol;1
On the lest side, click DOWNLOAD NOW. Install, run it-remove found threats.

Download Superantispyware from
http://download.cnet.com/SuperAntiSpywar...ag=mncol;2
Download it,install it, run it. Perform Quick Scan. Once scan is complete, click Show results-check all threats found and click Remove Threats.
(As a small PS- i choose Superantispyware over MBAM(Malwarebytes), simply because MBAM is not what it used to be, and Superantispyware actually cleans up where MBAM failed)

Download Cleaner from
http://download.cnet.com/CCleaner/3000-1...ag=mncol;1
Cleaner is a very useful tool that cleans your computer of temp files, history and cookies. Its also used to fix any registry errors.

[DunbarPappy®ϟϟ]

These mods should help deflect unwanted (and potentially dangerous) junk:
CHROME upper right chevron > Settings> tick "Show Advanced settings..." @ bottom> Privacy> Content settings> Cookies> (choose one of the top two), and "Block 3rd party..."
Tick * : Show images
Allow sites to run JavaScript"
(Plug-in's) Click to play
Do not allow pop-up's
Do not allow any site to track my physical location
Ask me when a site wants to show desktop notifications (recommended)
Do not allow any site to disable the mouse cursor
"Web intents"â‘¡ is a decision you must make.
[IMHO this is more spying and potential security risks.]
Do not allow sites to access my camera and microphone.
(You decide if this is needed for some feature)

* Only if you have the following plug-in's:
â–º"AdBlock Plus" (might need 'subscription' added after install).
https://chrome.google.com/webstore/search?q=ad+block
â–º"KB SSL Enforcer" add-on: https://chrome.google.com/webstore/detai...ofphddckof
â–º"ScriptSafe" stops all kinds of nasties and should be used by everyone. https://chrome.google.com/webstore/detai...lahbdbdgdf

â‘¡ Read carefully what this feature does because it has convoluted implications. https://en.wikipedia.org/wiki/Web_Intents
ADDITIONAL: Google Chrome: Best security tips for safer browsing; https://www.pcworld.com/article/2030873/...wsing.html