Quick Start Guide

March 26, 2026 · View on GitHub

Prerequisites

RequirementNotes
OSLinux, macOS, Windows
Privilegesroot or CAP_NET_RAW — raw packet capture requires elevated access
libpcap / npcapLinux: libpcap-dev; macOS: built-in; Windows: Npcap
Go (build only)1.23+

Installation

Visit Releases and download the binary for your platform.

# Linux x86_64
curl -L https://github.com/boy-hack/ksubdomain/releases/latest/download/ksubdomain_linux_amd64 \
     -o /usr/local/bin/ksubdomain
chmod +x /usr/local/bin/ksubdomain

Build from source

git clone https://github.com/boy-hack/ksubdomain.git
cd ksubdomain
# Inject version via ldflags (recommended)
go build -ldflags "-X github.com/boy-hack/ksubdomain/v2/pkg/core/conf.Version=v2.x.y" \
    -o ksubdomain ./cmd/ksubdomain

Your first scan

1 — Check available network interfaces

sudo ./ksubdomain device

2 — Test maximum packet rate

sudo ./ksubdomain test

3 — Enumerate subdomains (built-in wordlist)

sudo ./ksubdomain enum -d example.com

Sample output:

www.example.com => 93.184.216.34
mail.example.com => 93.184.216.50
api.example.com => 93.184.216.51

4 — Verify a domain list

sudo ./ksubdomain verify -f domains.txt -o output.txt

Common workflows

Pipe to httpx for HTTP probing

sudo ./ksubdomain enum -d example.com --only-domain --silent | httpx -silent

Save as JSONL for streaming processing

sudo ./ksubdomain enum -d example.com --format jsonl -o result.jsonl

Batch enumeration of multiple root domains

sudo ./ksubdomain enum --domain-list roots.txt -b 10m --format jsonl -o all.jsonl

Predict + advanced wildcard filter

sudo ./ksubdomain enum -d example.com --predict --wildcard-filter advanced -o result.txt

Multi-NIC parallel sending

sudo ./ksubdomain enum -d example.com --interface eth0 --interface eth1 -b 20m

Platform notes

Linux

# Grant CAP_NET_RAW instead of running as root (optional)
sudo setcap cap_net_raw+ep ./ksubdomain

./ksubdomain enum -d example.com

macOS

macOS uses BPF with smaller default buffers. Keep bandwidth conservative:

sudo ./ksubdomain enum -d example.com -b 5m

WSL / WSL2

./ksubdomain enum -d example.com --interface eth0

Windows

  1. Install Npcap (WinPcap is not supported)
  2. Run as Administrator
.\ksubdomain.exe enum -d example.com

Next steps