1. Investigate the type of traffic allowed to malicious domain (e.g web, dns, smtp).
2. Manually perform a validation of the internal machine connecting to this malicious domain and collect the destination IP address. Validate this IP address on external Threat Intell sources (e.g www.abuseIPdb.com, virustotal.com).
3. Identify the number of requests within a specific period of time which could be an solid indicator of a compromised host.
4. Perform a AV/AM scan for the affected internal machine