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.

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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:

1. Read page naturally
2. Does it feel spam-like?
3. Are keywords forced?
4. 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

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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:

1. Highlight all text on page
2. Look for invisible text
3. Check color contrast
4. 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:

1. Crawl site as regular user
2. Crawl site as Googlebot
3. Compare responses
4. 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;
}

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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

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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

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Success Metrics

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

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Related Skills:

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