ASSETFINDER

What is Assetfinder?

Assetfinder is a tool primarily designed for cybersecurity professionals and penetration testers to discover and enumerate domains and subdomains associated with a specific target domain. Written in Go (Golang), this tool aggregates data from various public sources to provide a comprehensive list of assets that could potentially be probed or exploited during an assessment. The primary goal of assetfinder is to aid in the reconnaissance phase of a security assessment. Reconnaissance is a crucial step in penetration testing and vulnerability assessments, where the attacker or assessor gathers as much information as possible about the target. By uncovering related domains and subdomains, professionals can identify a broader attack surface and subsequently check for potential vulnerabilities across these assets.

While its main function is to identify subdomains, its significance goes beyond mere enumeration. Each discovered subdomain can represent a different application, a different part of an organization's infrastructure, or even forgotten web assets that could be vulnerable to attacks. Hence, by revealing these assets, assetfinder helps in painting a more complete picture of a target's online presence. It's essential to underscore the importance of legal and ethical use of such tools. Scanning and probing domains without explicit permission is illegal and can lead to severe repercussions. Tools like assetfinder should only be employed in an environment where permission has been granted or during authorized security assessments.

What are the features of this tool?

• Domain and Subdomain Enumeration: Its primary function is to enumerate domains and subdomains associated with a target domain, aiding in the reconnaissance phase of security assessments.

• Aggregation from Multiple Sources: Assetfinder does not directly scan the target. Instead, it pulls data from various public sources such as certificate transparency logs, passive DNS databases, and more. This increases the likelihood of discovering a broad range of associated assets.

• Flexible Output Formats: While its default output is plaintext, the tool can produce results in JSON format using the -json flag, making it easier to integrate with other tools or scripts.

• Subdomain Filtering: With the -subs-only flag, users can filter out results to display only subdomains, excluding any unrelated domains.

• Speed and Efficiency: Being written in Go (Golang), assetfinder is fast and can handle large sets of data efficiently, which is essential when dealing with domains that have a vast number of associated assets.

• Easy Integration: Its simplicity and the ability to produce results in standardized formats mean that it can be easily integrated into larger reconnaissance workflows or automation pipelines.

• Open-Source: Assetfinder is open-source, which allows for community contributions, scrutiny, and custom modifications to fit specific needs.

• Focus on Passive Reconnaissance: The tool ensures that the enumeration process is passive, meaning it doesn't directly interact with the target domain or its assets. This reduces the risk of detection and ensures that the process is non-intrusive.

While these features make assetfinder a valuable tool, it's always recommended to use it in conjunction with other tools for a comprehensive and robust reconnaissance process.

Steps to install and use this tool in Kali Linux:-

Step1:- If you don't have Go installed, you'll need to do that first > using this command "sudo apt update   sudo apt install golang-go".

Step2:- Install assetfinder by using the command line "go install github.com/tomnomnom/assetfinder@latest"

Step3:- Once installed, assetfinder is straightforward to use by entering the command line "assetfinder example.com" > Replace "example.com" with the domain you want to investigate.

Step4:- For only subdomains enter command "assetfinder -subs-only example.com"