1. Investigate the type of traffic allowed to the malicious IP address (e.g web, dns, smtp).
2. Manually perform a validation of the malicious IP address on external Threat Intell sources (e.g www.abuseIPdb.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
5. Complete a Sentinel investigation for the same entity (IP address or user account) to understand if any other lateral attacks were completed while connecting to VPN to corporate network