DEV Community

MD Pabel
MD Pabel

Posted on • Originally published at mdpabel.com on

SEO Spam Malware Injection

Technical Analysis

The malware injects an HTML anchor tag into the page that links to an external site for SEO spamming purposes. It uses JavaScript to insert a CSS rule that hides the malicious content by setting the visibility of the div to be far off-screen (negative pixels), thus making it invisible to regular users while still being indexed by search engines.

VirusTotal Analysis: 🛡️ Zero-Day / Fully Undetected.

Attack Chain

  1. Step 1: Malware injects a hidden HTML div with an anchor link into the WordPress site.
  2. Step 2: A JavaScript function is executed that creates a CSS rule to hide the div from view.
  3. Step 3: The hidden div remains in the DOM, allowing search engines to index the SEO spam link.

Code Signature(s)

FILE: malware-sample.js 

<div id="M6bMm64IekltUmnGh3vrm9"><p><a href="https://andrikofarmakeio.com/">κοιτάξτε εδώ</a></p></div><script type="text/javascript">function oeYR5CtKOu7Yvb(){var mbO=document.getElementsByTagName('hea'+'d')[0];var JRm='#M6bMm64IekltUmnGh3vrm9{margin:0px 20px;position:fixed;overflow:hidden;top:-152413851px;display:block;z-index:412406018;}';var Ika8H=document.createElement('st'+'yl'+'e');Ika8H.type='text/css';if(Ika8H.styleSheet){Ika8H.styleSheet.cssText=JRm}else{Ika8H.appendChild(document.createTextNode(JRm))}mbO.appendChild(Ika8H)}oeYR5CtKOu7Yvb();</script>
Enter fullscreen mode Exit fullscreen mode

Indicators of Compromise (IOCs)

  • https://andrikofarmakeio.com/
  • #M6bMm64IekltUmnGh3vrm9
  • oeYR5CtKOu7Yvb()

Removal Protocol

  1. Step 1: Identify and remove malicious script injections from affected theme or plugin files.
  2. Step 2: Search the database for any injected links or scripts and remove them.
  3. Step 3: Install a WordPress security plugin to prevent future injections.

Status: Active Threat.

Verification: Verified by MD Pabel.

Top comments (0)