> ## Documentation Index
> Fetch the complete documentation index at: https://docs.snapsec.co/llms.txt
> Use this file to discover all available pages before exploring further.

# CRT.sh

> Fetch subdomains automatically from crt.sh certificate transparency logs into Snapsec AIM.

## CRT.sh Integration with Snapsec AIM

The **CRT.sh integration** allows Snapsec AIM to automatically fetch **subdomains** discovered through global Certificate Transparency (CT) logs.\
This helps identify hidden, forgotten, or shadow domains that appear in SSL certificates but are not tracked internally.

This guide explains how to:

1. Enable CRT integration in AIM
2. Automatically import subdomains from CT logs
3. Use the fetched data for inventory, threat analysis, and discovery

***

## Prerequisites

CRT.sh does **not require API keys** — only a domain or organization keyword to search.

You will need:

* A registered domain (e.g., `example.com`)
* Permission to manage AIM adapters
* (Optional) Asset classification rules to tag imported assets

***

## Installing the CRT Integration

1. Go to **AIM → Integrations**
2. Find **CRT** in the integrations list
3. Click **Install**

A dialog will appear prompting you to configure:

* **Domain / Root Domain** (required)
* **Polling Interval** (optional, default daily)

Click **Save** once complete.

![](https://mintlify.s3.us-west-1.amazonaws.com/snapsec-23724fa2/images/aim/integrations/crt.png)

CRT Integration Setup

***

## How CRT.sh Discovery Works

Once enabled, Snapsec AIM will:

### 🔍 Query CT Logs

Search CRT.sh for any certificate containing:

* Your domain
* Subdomains
* Wildcard certificates
* Historical certificates

### 🧩 Parse Certificate Records

AIM processes certificate CN/SAN entries to extract:

* Subdomain names
* Wildcard domain variants
* Past domains still visible in public logs

### 🔗 Add New Assets to Inventory

Imported subdomains appear in:

* **Subdomains Catalog**
* **Global Asset Inventory**
* Asset Relations Graph
* Exposure analysis workflows

Each subdomain is enriched with:

* DNS lookups
* Technologies
* IP mapping
* Risk Indicators

***

## How AIM Uses CRT Data

CRT integration helps solve several real problems:

### ✔ Identify Shadow Subdomains

Discover subdomains created without security approval but exposed publicly.

### ✔ Detect Legacy or Forgotten Environments

Old certificates reveal deprecated services still reachable online.

### ✔ Strengthen Surface Monitoring

New certificate issuance immediately alerts AIM to newly exposed assets.

### ✔ Enhance ASM + VM + TM Workflows

CRT-derived domains automatically flow into:

* Vulnerability scans
* Threat modeling projects
* Attack surface maps

***

## Troubleshooting

### ❗ No subdomains found

Ensure your root domain is correctly entered (e.g., `example.com`, not `https://example.com`).

### ❗ Too many results or noise

Use AIM classifiers to tag or filter unwanted entries.

### ❗ Duplicate records

AIM automatically deduplicates assets — duplicates will merge into a single asset entry.

***

## Next Steps

> [card] [View Subdomain Catalog](https://docs.snapsec.co/products/aim/subdomains)
>
> Explore all subdomains discovered from CRT and other adapters.


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.