root@thehacksparrow:~/writeups$ SYSTEM ONLINE
root@sparrow:~/writeups$ cat amass.md
// tools

OWASP Amass

22 Jul 2026 · 2 min read

What it is — Amass (an OWASP project) is the most thorough and aggressive subdomain enumeration tool in common use: it combines passive sources (like crt.sh or Sublist3r), active DNS resolution, brute forcing, and search engine scraping, all into a single graph of the target's infrastructure.

TypeCLI (Go)
CostFree, open source
Repogithub.com/owasp-amass/amass

How to use it

Passive enumeration (external sources only, never touches the target):

amass enum -passive -d domain.com

Active enumeration (adds DNS resolution and brute forcing):

amass enum -active -d domain.com

View the accumulated relationship graph from previous scans:

amass viz -d domain.com -d3

Active mode generates considerably more traffic against the target than crt.sh or Sublist3r — save it for when passive recon falls short, or when the program's scope explicitly allows it.

What I use it for

  • Final recon pass after crt.sh, DNSDumpster and Sublist3r — Amass often finds subdomains the lighter tools miss.
  • Mapping shared infrastructure: the graph mode helps see which subdomains point to the same IP or the same cloud provider.
  • Large bug bounty programs: when the scope includes the whole "*.company.com", Amass is the tool that actually squeezes that surface.

Link

github.com/owasp-amass/amass →