Configuring Microsoft Cloud App Security for Splunk: mcas siemagent install

In today's digital landscape, ensuring the security of cloud applications is paramount for organizations worldwide. Microsoft Cloud App Security (MCAS) provides robust tools for monitoring and protecting cloud applications. In this guide, we'll walk through the process of configuring MCAS for Splunk, leveraging a Splunk Heavy Forwarder to ingest and analyze MCAS logs. We'll cover essential steps, potential pitfalls, and troubleshooting tips to ensure a smooth setup.

Why Configure Microsoft Cloud App Security for Splunk?

As organizations increasingly rely on cloud services, the need to monitor and secure cloud applications becomes critical. By integrating MCAS with Splunk, organizations gain centralized visibility into cloud app activities, enabling proactive threat detection and rapid incident response. This integration facilitates comprehensive security monitoring, compliance reporting, and actionable insights to bolster overall cybersecurity posture.

Prerequisites

Before diving into configuration, ensure you have the following prerequisites:

  • A standard Windows or Linux server (virtual or physical).
  • Operating System: Windows or Linux.
  • Adequate CPU, disk space, and RAM as per requirements.
  • Access to Microsoft 365 Defender portal and firewall settings.
  • MCAS SIEM agent (.jar file).
  • Java 8 installed on the server.

Procedure

1. Obtain Token for SIEM Agent

  • Access the Microsoft 365 Defender portal and configure the SIEM agent for Cloud Apps.
  • Save the generated token securely for future use.

2. Download and Test the SIEM Agent

  • Download the MCAS SIEM agent from the Microsoft website.
  • Transfer the agent to the target host using SCP or Wget.
  • Ensure Java 8 is installed on the host.
  • Test the SIEM agent using the provided token.

java -jar /path/to/mcas-siemagent-0.111.126-signed.jar --logsDirectory "/tmp" --token "YOUR_TOKEN" &
 
  • Monitor logs for any errors and troubleshoot as needed. Common issues may include SSL handshake failures due to firewall restrictions.

3. Configure Rsyslog and Splunk Inputs

  • Configure Rsyslog to route SIEM agent logs to a designated file.
  • Forward these logs to Splunk using the appropriate inputs configuration.
# Rsyslog Configuration
template(name="cloud" type="string" string="/opt/splunk/var/log/syslog/generic/%fromhost%/ms_cloud_app_security_syslog.log")
$RuleSet genericudp
if ($msg contains 'SIEM_Agent') then
{
action(type="omfile" Dynafile="cloud" template="rawmsg" dirOwner="splunk" dirGroup="splunk" fileOwner="splunk" fileGroup="splunk") & stop
}
 
# Splunk Inputs Configuration
[monitor:///opt/splunk/var/log/syslog/generic/<RemoteServerName>/*.log]
sourcetype = ms:cas:syslog
index = cas_index
disabled = 0

4. Configure Crontab for Agent Initialization

  • Ensure the SIEM agent initializes on server startup by adding a cron job.

@reboot java -jar /path/to/mcas-siemagent-0.111.126-signed.jar --token "YOUR_TOKEN"

5. Verify Data in Splunk

  • Allow some time for the SIEM agent to send data to Splunk.
  • Verify data ingestion in Splunk by searching for relevant events.

index=cas_index host=RemoteServerName

Conclusion

Integrating Microsoft Cloud App Security with Splunk offers organizations a powerful solution for monitoring and securing cloud applications. By following this comprehensive guide, you can configure MCAS for Splunk seamlessly, enabling proactive threat detection and enhancing overall cybersecurity resilience.

For additional information and resources, refer to the sources provided below. Stay vigilant, stay secure!

Sources

With this guide, you're equipped to harness the combined power of Microsoft Cloud App Security and Splunk for enhanced cloud security and threat detection.