Overview
SkipFish is a fast, active web application reconnaissance tool originally from Google. It crawls a target, probes with a dictionary of paths and payloads, and produces an interactive HTML report grouping findings by severity. SkipFish is noisy by design — it is meant for authorized assessments of your own apps, not stealthy scans of third parties. Pair with Burp/ZAP for manual follow-up on the findings it surfaces.
Instructions
Step 1: Install and Pick a Dictionary
bash
# Kali
sudo apt install -y skipfish
# From source
git clone https://github.com/spinkham/skipfish.git
cd skipfish && make
# Dictionaries ship in /usr/share/skipfish/dictionaries/
ls /usr/share/skipfish/dictionaries/
# complete.wl extensions-only.wl minimal.wl medium.wl
# Rules of thumb:
# minimal.wl → very fast first pass (~30 min)
# medium.wl → balanced (1–4 hours)
# complete.wl → deep (overnight)
Step 2: Run a Basic Scan
bash
# Output directory must not exist — skipfish creates it
rm -rf ./report
skipfish -W /usr/share/skipfish/dictionaries/minimal.wl \
-o ./report \
http://webapp.local/
# Open the report
xdg-open ./report/index.html
# Findings grouped: High / Medium / Low / Warnings / Info
Step 3: Scope the Crawl
bash
# Limit to a single host (don't chase off-site links)
skipfish -o report -W minimal.wl \
-I '^http://webapp\.local/' \
http://webapp.local/
# Exclude paths that destroy state
skipfish -o report -W minimal.wl \
-X '/logout' -X '/admin/delete' \
http://webapp.local/
# Limit depth and request count (time-box the scan)
skipfish -o report -W minimal.wl \
-d 5 -c 10 -l 1000 \
http://webapp.local/
# -d max crawl depth, -c max children per node, -l max total requests
Step 4: Authenticated Scans
bash
# Form-based auth — pre-authenticate and pass the cookie
COOKIE=$(curl -s -c - -d 'user=admin&pass=hunter2' \
http://webapp.local/login | awk '/session/ {print $7}')
skipfish -C "session=$COOKIE" \
-X /logout \
-o report-authed \
-W /usr/share/skipfish/dictionaries/minimal.wl \
http://webapp.local/dashboard
# Multiple cookies
skipfish -C "session=abc123" -C "csrftoken=def456" -o report http://webapp.local/
# HTTP Basic auth
skipfish -A admin:hunter2 -o report http://webapp.local/
Step 5: Tune Performance and Politeness
bash
# Polite scan for shared/staging environments
skipfish -W minimal.wl -o report \
-m 5 -t 10 \
http://staging.webapp.local/
# -m max concurrent connections (default 10)
# -t request timeout seconds
# Aggressive scan on your own dev box
skipfish -W medium.wl -o report \
-m 25 -t 5 \
http://127.0.0.1:8000/
Examples
Example 1: Fast Triage of a New Web App
bash
# 30-minute first pass before manual testing
rm -rf ./first-pass
skipfish \
-W /usr/share/skipfish/dictionaries/minimal.wl \
-I '^http://app\.example\.internal/' \
-X /logout -X /shutdown \
-d 4 -c 8 -l 2000 \
-o ./first-pass \
http://app.example.internal/
# Review index.html, look for:
# - XSS vectors (High)
# - SQL errors in responses (High)
# - Directory listings (Medium)
# - Backup files (.bak, .swp, ~) (Medium)
# - Exposed VCS dirs (.git, .svn) (High)
# Every finding → manually verify in Burp before reporting
Example 2: Authenticated Scan of an Internal Dashboard
bash
# Acquire a valid session cookie
CJ=$(mktemp)
curl -s -c "$CJ" -d 'username=tester&password=Acme2026!' \
-X POST http://internal.acme.local/auth/login >/dev/null
SESSION=$(awk '/session/ {print $7}' "$CJ")
rm -f "$CJ"
rm -rf ./auth-scan
skipfish \
-C "session=$SESSION" \
-X /auth/logout \
-X /users/delete \
-I '^http://internal\.acme\.local/' \
-W /usr/share/skipfish/dictionaries/medium.wl \
-o ./auth-scan \
http://internal.acme.local/
xdg-open ./auth-scan/index.html
Guidelines
- Written authorization is mandatory. SkipFish sends destructive-looking payloads — run it against your own apps, staging, or in-scope targets only.
- Exclude state-changing endpoints (
/logout,/delete,/admin/reset) with-X. SkipFish will happily crawl them otherwise. - Dictionary choice dominates runtime:
minimal.wlfor a quick pass,medium.wlfor a real assessment,complete.wlfor overnight work. - Start with
-Ito clamp the crawl scope — otherwise SkipFish wanders across subdomains and partners. - Expect false positives. SkipFish is a funnel; manually verify every finding before it goes in the report.
- The HTML report is the primary output — browse it with
index.html, not the raw logs. - SkipFish is legacy but still useful for fast active recon. For modern web apps with SPAs and GraphQL, combine with Burp, ZAP, and ffuf.
- Never scan production without the customer's explicit sign-off and a change window; dictionary attacks generate alerts and load.