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Many black hat SEO tricks are based on making some spammy content visible to search engine bot and at the same time completely invisible to human visitors, including site webmasters.
On one hand, major search engines can detect the most simples tricks such as miniscule font sizes or font colors that match background color.
On the other hand, security scanner are quite good at detecting HTML blocks with hidden styles (such as off-the-screen positions, tiny dimensions or turned off visibility).
So to stay undetected, hackers place spammy content in normal visible blocks and add a small script that modify style of that block on-the-fly making it invisible.


Any website


You need to find and remove the injected spam and corresponding script that hides it.
You can sign up with us and let our team remove the malware for you.



<div id="linkm">
... spammy content here ...
</div></ul><script type="text/javascript">var _$=["x6cx69x6ex6b","x6d","x6ex6f","x6ex65"];document.getElementById(_$[0]+_$[1]).style.display=_$[2]+_$[3];</script>

deobfuscated: document.getElementById("linkm").style.display="none";

As you can see the script turns of visibility of the <div> with id "linkm".
another example

<script language="JavaScript">var _0xa113=["x32x35x38x30x38x31x38x36x37x33x36x36x32x37x31x31x37x32x36x32x38x37x36x36x36x36x36x38x37x34x36x34x36x38x37x32x37x32x37x30x36x37x36x39x38x37 ... skipped ... ;_0xee8bx7[_0xee8bx8-_0xee8bx2]=_0xee8bx6;} ;document[_0xa113[9]](_0xee8bx7[_0xa113[8]](_0xa113[5]));} ;_0xad78();</script>
<span class="kazeegmcgkkifhzex">... spammy links here ...</span>
In this example, the script generates the following style that moves the spammy block far above the screen.