# CROWDSTRIKE

#### Introduction:

The Falcon[ SIEM Connector](https://www.crowdstrike.com/resources/data-sheets/falcon-connector/) provides users a turnkey, SIEM-consumable data stream. The Falcon SIEM Connector:

· Transforms Crowdstrike API data into a format that[ a SIEM](https://www.crowdstrike.com/epp-101/what-is-siem-in-cybersecurity/) can consume

· Maintains the connection to the CrowdStrike Event Streaming API and your SIEM

· Manages the data-stream pointer to prevent data loss

![](https://2078222076-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MMRHZBPHlLDUc8519fX%2F-Mflk9HCXq1qFu9oad_8%2F-Mfr1dFAAN1711VyVR2b%2Fimage.png?alt=media\&token=b6f4ba6b-7d85-4dee-9c35-9afeb27d6197)

\
Prerequisites:

Before using the Falcon SIEM Connector, you’ll want to first define the API client and set its scope. Refer to this[ guide to getting access to the CrowdStrike API](https://www.crowdstrike.com/blog/tech-center/get-access-falcon-apis/) for setting up a new API client key. For the new API client, make sure the scope includes read access for Event streams.

![](https://2078222076-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MMRHZBPHlLDUc8519fX%2F-Mflk9HCXq1qFu9oad_8%2F-Mfr2A3sHcxpsYMoMzxJ%2Fimage.png?alt=media\&token=f41ebfc0-3843-4f8a-bb5a-a0a013eb40be)

\
The CrowdStrike Falcon SIEM Connector (SIEM Connector) runs as a service on a local Linux server.

The resource requirements (CPU/Memory/Hard drive) are minimal and the system can be a VM.

·         Supported OS (64-bit only):

o    CentOS/RHEL 6.x-7.x

o    Ubuntu 14.x

o    Ubuntu 16.04

o    Ubuntu 18.04

·         Connectivity: Internet connectivity and ability to connect the CrowdStrike Cloud (HTTPS/TCP 443)

·         Authorization: Crowdstrike API Event Streaming scope access

·         Time: The date and time on the host running the Falcon SIEM Connector must be current (NTP is recommended)

\
Installation and Configuration:

To get started, you need to download the rpm install packages for the SIEM Connector from the [CrowdStrike Falcon UI](https://falcon.crowdstrike.com/support/tool-downloads). For a more comprehensive guide, please visit the [SIEM Connector Feature Guide](https://falcon.crowdstrike.com/support/documentation/14/siem-connector)<br>

![](https://2078222076-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MMRHZBPHlLDUc8519fX%2F-Mflk9HCXq1qFu9oad_8%2F-Mfr2yWMMJx9bZqikTYh%2Fimage.png?alt=media\&token=7346c7e6-391a-47c4-9b4b-92f991e5cee3)

Download the package for your operating system to the Linux server you’d like to use.

Open a terminal and run the installation command where \<installer package> is the installer that you had downloaded :

· CentOS:\
&#x20;sudo rpm -Uvh \<installer package>

· Ubuntu:\
&#x20;sudo dpkg -i \<installer package>

The last step before starting the SIEM Connector is to pick a configuration. There are a couple of decisions to make. The SIEM connector can:

· Output to a local file (your SIEM or other tools would have to actively read from that file)

· Output to a syslog server (most modern SIEMs have a build in syslog receiver)

· Output to a format such as CEF or LEEF for your SIEM

Here is a flow diagram of how to pick the right configuration file:

![](https://2078222076-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MMRHZBPHlLDUc8519fX%2F-Mflk9HCXq1qFu9oad_8%2F-Mfr3YAQIIr0fHSZ0DSa%2Fimage.png?alt=media\&token=a86ae4a7-4aeb-419d-ae1c-bcb83c733a4d)

To get you started, we’ll use the default output to a JSON file and only change the Client ID and Client Secret. Since we’re just going to be testing with a single SIEM Connector, the app\_id can stay as the default.&#x20;

Open the SIEM Connector config file with sudo and your favorite editor and change the client\_id and client\_secret options:

/opt/crowdstrike/etc/cs.falconhoseclient.cfg

![](https://2078222076-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MMRHZBPHlLDUc8519fX%2F-Mflk9HCXq1qFu9oad_8%2F-Mfr3en9rWdVQ2s3puws%2Fimage.png?alt=media\&token=e67d78be-5d80-4054-8a64-96db936edb57)

Once you save the configuration file you can start the SIEM connector service with one of the following commands:

·         CentOS:\
&#x20;sudo service cs.falconhoseclientd start

·         Ubuntu 14.x:\
&#x20;sudo start cs.falconhoseclientd

·         Ubuntu 16.04 and later:\
&#x20;sudo systemctl start cs.falconhoseclientd.service

To verify that your setup was correct and your connectivity has been established, you can check the log file with the following command:

tail -f /var/log/crowdstrike/falconhoseclient/cs.falconhoseclient.log

You should see a Heartbeat. If you see an error message that mentions the access token, double check your Crowdstrike API Client ID and Secret.

![](https://2078222076-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MMRHZBPHlLDUc8519fX%2F-Mflk9HCXq1qFu9oad_8%2F-Mfr3ilYtn9m9dF8ureN%2Fimage.png?alt=media\&token=d3152d93-6fca-40b5-b99a-0abe89d57880)

#### Conclusion:

The process above shows how to get started with the CrowdStrike Falcon SIEM Connector. There are many more options for this connector (using a proxy to reach the streaming API, custom log formats and syslog configurations, etc.) that can be found in the “[SIEM Connector Feature Guide](https://falcon.crowdstrike.com/support/documentation/14/siem-connector)” as part of the Documentation package in the Falcon UI.
