seo-spam-detection

SEO Spam Detection

Comprehensive detection of black-hat SEO techniques and spam indicators. Protects against policy violations and search penalties.

Purpose

Audit for SEO spam:

Detect keyword stuffing
Find hidden text/links
Identify cloaking techniques
Flag spammy backlinks
Detect comment spam
Prevent search engine penalties

Quick Start

Input: Website URL or source files Output: Spam detection report + risk assessment Time: 20-40 minutes

Scoring Mode & Aggregation Contract

This skill is the main Search Integrity contributor and should align to the benchmark scope explicitly:

Core 79: required coverage is SI01-SI12
Core 79 + Profile: required coverage is SI01-SI12 plus any SI extension items selected by profile or trigger rules
Full 105: cover SI01-SI16

Structured results should declare:

score_mode
covered_items
selected_profile_items limited to SI items
triggered_extension_items limited to SI items
manual_review_required when evidence is directional but not conclusive

If this skill finds issues in SI13-SI16 while running Core 79, mark them as extension_findings so the aggregator can decide whether to widen scope.

Keyword Stuffing Detection

What is Keyword Stuffing?

Loading page with keywords unnaturally to improve rankings.

Examples:

❌ "Buy shoes, cheap shoes, best shoes, shoes online, discount shoes..."
❌ Repeating keyword 5+ times in 100 words
❌ Keywords unrelated to actual content

Good Density (~1-2% of words):

500-word article → 5-10 uses of keyword
Natural language reads naturally

Bad Density (>5%):

Keyword appears forced or repeated
Sentences don't flow naturally
Content feels spam-like

Detection Process

Manual Check:

Read page naturally
Does it feel spam-like?
Are keywords forced?
Would actual user enjoy this?

Automated Check:

function checkKeywordDensity(text, keyword) {
  const words = text.toLowerCase().split(/\s+/);
  const keywordCount = words.filter(
    word => word.includes(keyword.toLowerCase())
  ).length;

  const density = (keywordCount / words.length) * 100;

  // Red flags
  if (density > 5) return { spam: true, reason: 'High keyword density' };
  if (density > 3 && !naturalLanguage(text)) return { spam: true, reason: 'Forced keywords' };

  return { spam: false };
}

Tools:

SEMrush Keyword Density
Moz Keyword Tool
SurferSEO density check

Hidden Text & Links Detection

Hidden Text Techniques

Method 1: White Text on White Background

<div style="color: #fff; background: #fff;">
  keyword keyword keyword
</div>

Method 2: Font Size 0

<div style="font-size: 0;">keyword spam</div>

Method 3: Off-Page Positioning

.spam {
  position: absolute;
  left: -9999px; /* Off-screen */
}

Method 4: Comments or Metadata

<!-- hidden keyword spam -->
<meta name="hidden" content="keyword spam">

Detection

Visual Check:

Highlight all text on page
Look for invisible text
Check color contrast
Check font sizes

Code Check:

# Find suspicious CSS
grep -r "color: #fff" *.html
grep -r "font-size: 0" *.html
grep -r "left: -999" *.css
grep -r "display: none" *.css # If non-accessible

Automated Check:

function findHiddenText(element) {
  const style = window.getComputedStyle(element);
  const issues = [];

  // Check visibility
  if (style.display === 'none') issues.push('Hidden with display:none');
  if (style.visibility === 'hidden') issues.push('Hidden with visibility:hidden');
  if (style.opacity === '0') issues.push('Hidden with opacity:0');

  // Check positioning
  const left = parseInt(style.left);
  if (left < -100) issues.push('Off-screen text');

  // Check color contrast
  const color = style.color;
  const bg = style.backgroundColor;
  if (contrast(color, bg) < 1) issues.push('No contrast (hidden)');

  return issues;
}

Cloaking Detection

What is Cloaking?

Showing different content to users vs. search engines.

Example:

Googlebots see "Premium SEO Content"
Users see "Click here for free money"

Detection Process

Check User-Agent:

Crawl site as regular user
Crawl site as Googlebot
Compare responses
If different: 🚩 Cloaking detected

Tools:

Google Search Console (Fetch as Google)
SEMrush Site Audit
Moz Crawl

Manual Check:

# Check as user
curl -H "User-Agent: Mozilla/5.0" https://example.com/page

# Check as Googlebot
curl -H "User-Agent: Mozilla/5.0 (compatible; Googlebot/2.1)" https://example.com/page

# Compare output (should be identical)
diff user-agent-response.html googlebot-response.html

Spammy Backlinks Detection

Red Flag Link Patterns

Low-Quality Link Farms:

❌ Links from directories with 10k+ sites
❌ Links from unrelated sites
❌ Links from known PBN (Private Blog Networks)
❌ Links with anchor text too similar to target keyword

Unnatural Patterns:

❌ 100 links added in 1 day
❌ Links from auto-generated sites
❌ Links from sites with 0 traffic
❌ Exact match anchor text 50%+ of links

Analysis Process

Step 1: Get Backlinks

# Using SEMrush, Moz, Ahrefs, or similar:
# Export all backlinks to CSV

Step 2: Categorize

✅ Quality backlinks:
- News sites
- Industry publications
- Educational institutions
- High authority domains (DA >40)
- Natural, varied anchor text

⚠️ Questionable backlinks:
- Blogs that accept any content
- PBN indicators
- Exact match keywords 30-50%
- Recent bulk additions

❌ Spam backlinks:
- Obvious PBN (similar design/content)
- Exact match keywords 70%+
- Link farms
- Adult/gambling/pharmaceutical
- Automated comments

Step 3: Analyze Patterns

function analyzeBacklinks(links) {
  let spam_score = 0;

  // Check anchor text ratio
  const exactMatch = links.filter(l => 
    l.anchor === targetKeyword
  ).length;
  if (exactMatch / links.length > 0.5) spam_score += 30;

  // Check domain authority
  const lowDA = links.filter(l => l.domainAuthority < 20).length;
  if (lowDA / links.length > 0.7) spam_score += 20;

  // Check diversity
  const uniqueDomains = new Set(links.map(l => l.domain)).size;
  if (uniqueDomains / links.length < 0.8) spam_score += 15;

  return spam_score;
}

Disavow Bad Links

If you find spam links:

# Create disavow file
disavow.txt:
domain spam-site-1.com
domain spam-site-2.com
url https://bad-site.com/link-to-me

# Submit to Google Search Console

Comment Spam Detection

Red Flags

Spam Comment Indicators:

Generic praise ("Great post!")
Links in comment text
Unrelated to content
Multiple similar comments
Foreign language comments
Links to unrelated sites

Prevention

WordPress:

Enable Akismet (catches 90%+)
Require approval
Moderate comments
Check for spammy URLs

Custom Systems:

function isSpamComment(comment) {
  const spam_score = 0;

  // Generic praise
  if (/great post|nice article|thanks for sharing/.test(comment.text)) 
    spam_score += 20;

  // Links in comment
  if (comment.text.includes('http')) spam_score += 30;

  // Very short comment
  if (comment.text.length < 20) spam_score += 15;

  // All caps
  if (comment.text === comment.text.toUpperCase()) spam_score += 15;

  return spam_score > 50;
}

SEO Spam Checklist

Content:

No keyword stuffing (density <3%)
No hidden text or links
Natural, readable language
Valuable to users

Technical:

No cloaking for different user agents
Same content for all users/crawlers
No redirect tricks
robots.txt not hiding content

Links:

No unnatural link patterns
Anchor text naturally varied
No obvious PBN links
Link growth normal/gradual

Comments:

Comment spam moderated
No spam links in comments
Legitimate user discussion only

Spam Detection Report

# SEO Spam Detection Report

## Keyword Stuffing
- Pages analyzed: 150
- Keyword density average: 1.8%
- High density (>5%): 0 pages
- Suspicious patterns: 0
- Status: ✅ CLEAN

## Hidden Text/Links
- Pages scanned: 150
- Hidden text found: 0
- Off-screen content: 0
- Hidden links: 0
- Status: ✅ CLEAN

## Cloaking
- User-agent test: PASSED
- Content identical for all: ✅
- Googlebot sees same: ✅
- Status: ✅ CLEAN

## Backlink Analysis
- Total backlinks: 45
- Quality backlinks: 40 (89%)
- Questionable: 5 (11%)
- Spam backlinks: 0 (0%)
- Spam score: LOW

### Action Items
- Review 5 questionable links
- Disavow any confirmed spam

## Comment Spam
- Total comments: 320
- Spam detected: 3 (1%)
- Status: ✅ MINIMAL

## Overall Risk
- Risk level: LOW
- Recommendations: Monitor backlinks quarterly

Automation Tools

Built-In Options:

Google Search Console (organic search data)
Google Analytics (spam traffic detection)
Yoast SEO (WordPress plugin)

Professional Tools:

SEMrush Site Audit
Moz Pro
Ahrefs
Surfer SEO
Screaming Frog

Success Metrics

Zero keyword stuffing
Zero hidden text/links
Zero cloaking indicators
<5% spam backlinks
Minimal comment spam
No manual penalties from Google

Related Skills:

Policy compliance → policy-risk-scanner
Full audit → ads-readiness-assessment
Monitoring → active-compliance-monitor

About this skill

Purpose

Quick Start

Scoring Mode & Aggregation Contract

Keyword Stuffing Detection

What is Keyword Stuffing?

Detection Process

Hidden Text & Links Detection

Hidden Text Techniques

Detection

Cloaking Detection

What is Cloaking?

Detection Process

Spammy Backlinks Detection

Red Flag Link Patterns

Analysis Process

Disavow Bad Links

Comment Spam Detection

Red Flags

Prevention

SEO Spam Checklist

Spam Detection Report

Automation Tools

Success Metrics