Good command-and-control infrastructure requires a known, trusted domain. When you’re first starting out, this can be difficult to find, but luckily other testers have provided many great resources.

So, let’s dive into what’s available and how to make the right choices when building out an attack infrastructure.

ID and purchase the best domains

First things first: purchase a domain. In this process, you’ll most likely consider either of the following options:

  • Purchasing a domain similar to your target's apex domain

  • Purchasing a domain with an existing and strong reputation

If you’re looking for a domain similar to your target domain, check out the link below:

dnstwister The anti-phishing domain name search engine, based on dnstwist.

Search your target apex domain and this site will help you find similar ones for sale. For example, I performed a search for our company domain:

dnstwister Report

Additionally, good place to look for reputable domains to purchase is linked below:

Expired Domains | Daily Updated Domain Lists for 472 TLDs You can currently find the following domains in the database. The lists get updated regularly and new domains get added to the database.

This place is the cream of the crop when it comes to looking for reputable domain names. I’d recommend creating an account so you can browse and save your finds. To uncover the good stuff, go to deleted domains: Deleted Domains

Select the filter option: Filter Options

Try out my go-to filter settings: Filter Settings - Columns

You can also tab over and choose from a set of desired TLD's and SEO categorizations. Don’t worry too much about domain categorization; we can consider that at a later point. For now, click "Apply Filter" and you’re on your way.

Each column header is related to something different. I like to find a domain with a large number of backlinks from other domains. This means the domain has been around and used – therefore, the chances of this domain being marked as malicious are pretty low. Column Manager

Some other indicators I look for when buying domains:

  • Length. Look to pick fairly short domains. The longer the domain, the more it stands out to defenders.

  • Lifetime. Pick domains that have been around for a bit. This is indicated by the ABY and WBY column headers.

  • Association. A high number of [] crawl results also indicate that the domain is associated with known sites. You can actually go back and grab the page content to rehost the original site while aging the domain.

After you have selected some domains, you need to take a few steps before finalizing a purchase. I recently made the mistake of purchasing a domain that met the above criteria but ended up being permanently categorized by security solutions as unsavory.

To prevent something similar from happening to you, grab your domain and head to the following sites to perform a search:

Internet Archive: Digital Library of Free & Borrowable Books, Movies, Music & Wayback Machine Internet Archive is a non-profit digital library offering free universal access to books, movies & music, as well as 468 billion archived web pages.

Make sure your domain was never registered in association with malicious content or unsavory websites.

How to age a domain

After you purchase a domain, you need to build its reputation. This may be difficult depending on how long the domain has previously been in use. This is why it’s important to buy your domains far in advance and effectively keep track of what you have.

So, let's say you bought []. Some key next steps would be:

  • Setup reliable DNS records.

  • Setup fake sites associated with your domain.

  • Link your domain to a trusted mail server.

  • You can even send out some benign mail with it.

If you specifically want to use this domain for phishing, do the following:

  • Set up your mail records as soon as possible.

  • Don't do anything goofy.

  • ALWAYS have proper mail records set up, including having proper DKIM and SPF record provisions.

For hosting sites and your payloads:

  • Set up your records early.

  • Get a certificate associated with it.

  • Host a site with valid content and do so early in the process.

  • Point it at some known records similar to your site's categorization.

Wrapping Up

In a future article, I’ll outline the process for cloning sites and warming up infrastructure. Some great tools are out there to help with this process. And, we may even take a look at automation to make our lives easier.

For now, remember these key takeaways:

  • Buy your domains ahead of time.

  • Age your infrastructure to build trust.

You can never spend too much time on this. Good infrastructure will make or break an engagement.