amass

README

OWASP Amass

---

The OWASP Amass tool obtains subdomain names by scraping data sources, recursive brute forcing, crawling web archives, permuting/altering names and reverse DNS sweeping. Additionally, Amass uses the IP addresses obtained during resolution to discover associated netblocks and ASNs. All the information is then used to build maps of the target networks.

---

How to Install

Prebuilt

A precompiled version is available for each release.

If you are on a distribution such as Kali Linux, and have never used snap previously, follow these steps to access snap packages:

$ sudo apt install snapd

$ sudo systemctl start snapd

Add the snap binaries to your PATH using a method similar to the following:

$ export PATH=$PATH:/snap/bin

If your operating environment supports Snap, you can click here to install, or perform the following from the command-line:

$ sudo snap install amass

If you would like snap to get you the latest unstable build of OWASP Amass, type the following command:

$ sudo snap install --edge amass

From Source

If you would prefer to build your own binary from the latest version of the source code, make sure you have a correctly configured Go >= 1.10 environment. More information about how to achieve this can be found on the golang website. Then, take the following steps:

1. Download amass:

$ go get -u github.com/OWASP/Amass/...

1. If you wish to rebuild the binaries from the source code:

$ cd $GOPATH/src/github.com/OWASP/Amass

$ go install ./...

At this point, the binaries should be in $GOPATH/bin.

1. Several wordlists can be found in the following directory:

$ ls $GOPATH/src/github.com/OWASP/Amass/wordlists/

Using the Tool

The most basic use of the tool, which includes reverse DNS lookups and name alterations:

$ amass -d example.com

If you need Amass to run faster and only use the passive data sources:

$ amass -nodns -d example.com

If you are running Amass within a virtual machine, you may want to slow it down a bit:

$ amass -freq 480 -d example.com

The example below is a good place to start with amass:

$ amass -v -ip -brute -min-for-recursive 3 -d example.com
[Google] www.example.com
[VirusTotal] ns.example.com
...
13139 names discovered - archive: 171, cert: 2671, scrape: 6290, brute: 991, dns: 250, alt: 2766

Add some additional domains to the enumeration:

$ amass -d example1.com,example2.com -d example3.com

Additional switches available through the amass CLI:

Flag	Description	Example
-active	Enable active recon methods	amass -active -d example.com net -p 80,443,8080
-bl	Blacklist undesired subdomains from the enumeration	amass -bl blah.example.com -d example.com
-blf	Identify blacklisted subdomains from a file	amass -blf data/blacklist.txt -d example.com
-brute	Perform brute force subdomain enumeration	amass -brute -d example.com
-df	Specify the domains to be enumerated via text file	amass -df domains.txt
-freq	Throttle the rate of DNS queries by number per minute	amass -freq 120 -d example.com
-h	Show the amass usage information	amass -h
-ip	Print IP addresses with the discovered names	amass -ip -d example.com
-json	All discoveries written as individual JSON objects	amass -json out.json -d example.com
-l	List all the domains to be used during enumeration	amass -whois -l -d example.com
-log	Log all error messages to a file	amass -log amass.log -d example.com
-min-for-recursive	Discoveries required for recursive brute forcing	amass -brute -min-for-recursive 3 -d example.com
-noalts	Disable alterations of discovered names	amass -noalts -d example.com
-nodns	A purely passive mode of execution	amass -nodns -d example.com
-norecursive	Disable recursive brute forcing	amass -brute -norecursive -d example.com
-o	Write the results to a text file	amass -o out.txt -d example.com
-oA	Output to all available file formats with prefix	amass -oA amass_scan -d example.com
-r	Specify your own DNS resolvers	amass -r 8.8.8.8,1.1.1.1 -d example.com
-rf	Specify DNS resolvers with a file	amass -rf data/resolvers.txt -d example.com
-v	Output includes data source and summary information	amass -v -d example.com
-version	Print the version number of amass	amass -version
-w	Change the wordlist used during brute forcing	amass -brute -w wordlist.txt -d example.com
-whois	Search using reverse whois information	amass -whois -d example.com

Have amass send all the DNS and infrastructure enumerations to the Neo4j graph database:

$ amass -neo4j neo4j:DoNotUseThisPassword@localhost:7687 -d example.com

Here are switches for outputting the DNS and infrastructure findings as a network graph:

Flag	Description	Example
-d3	Output a D3.js v4 force simulation HTML file	amass -d3 network.html -d example
-gexf	Output to Graph Exchange XML Format (GEXF)	amass -gephi network.gexf -d example.com
-graphistry	Output Graphistry JSON	amass -graphistry network.json -d example.com
-visjs	Output HTML that employs VisJS	amass -visjs network.html -d example.com

amass.netnames

Caution: If you use the amass.netnames tool, it will attempt to reach out to every IP address within the identified infrastructure and obtain names from TLS certificates. This is "loud" and can reveal your reconnaissance activities to the organization being investigated.

To discover all domains hosted within target ASNs, use the following option:

$ amass.netnames -asn 13374,14618

To investigate within target CIDRs, use this option:

$ amass.netnames -cidr 192.184.113.0/24,104.154.0.0/15

For specific IPs or address ranges, use this option:

$ amass.netnames -addr 192.168.1.44,192.168.2.1-64

By default, port 443 will be checked for certificates, but the ports can be changed as follows:

$ amass.netnames -cidr 192.168.1.0/24 -p 80,443,8080

Integrating OWASP Amass into Your Work

If you are using the amass package within your own Go code, be sure to properly seed the default pseudo-random number generator:

import(
    "fmt"
    "math/rand"
    "time"

    "github.com/OWASP/Amass/amass"
)

func main() {
    output := make(chan *amass.AmassOutput)

    go func() {
        for result := range output {
            fmt.Println(result.Name)
        }
    }()

    // Seed the default pseudo-random number generator
    rand.Seed(time.Now().UTC().UnixNano())

    // Setup the most basic amass configuration
    config := amass.CustomConfig(&amass.AmassConfig{Output: output})
    config.AddDomain("example.com")

    amass.StartEnumeration(config)
}

Settings for the OWASP Amass Maltego Local Transform

1. Setup a new local transform within Maltego:

1. Configure the local transform to properly execute the go program:

1. Go into the Transform Manager, and disable the debug info option:

Community

• Discord Server - Discussing OSINT, network recon and developing security tools using Go

Mentions

• Paul's Security Weekly #564: Technical Segment - Bug Bounty Hunting
• Doing Recon the Correct Way
• Discovering subdomains
• Best Hacking Tools List for Hackers & Security Professionals 2018
• Amass - Subdomain Enumeration Tool
• Subdomain enumeration
• Asset Discovery: Doing Reconnaissance the Hard Way
• Go is for everyone
• Top Five Ways the Red Team breached the External Perimeter