You may observe the following issues:
1. Connections to the host(s) drop unexpectedly.
2. Multiple hostdCgiServer-zdump files created in /var/core
3. In a DRS cluster, DRS may move all VM's to a single host, or fewer hosts due to the service crashes making these hosts unavailable for DRS.
4. You see the following or similar in the vobd.log file:
[UserWorldCorrelator] 646511084069us: [esx.problem.hostd.core.dumped] /bin/hostdCgiServer crashed (3 time(s) so far) and a core file may have been created at /var/core/hostdCgiServer-zdump.002. This may have caused connections to the host to be dropped.
5. The customer is utilizing a Qualys scanning tool in their environment, or possibly another similar tool/script.