I have installed Splunk Enterprise Security (ES) and the Clam AV apps. Searching
tag=malware tag=attack works, bringing up the expected event. I can even see it in the visualizations. But I am not seeing it the host itself showing as infected. Any idea why? Very new to ES so I am not sure where to start on troubleshooting this.
A few things I noticed from your picture. I'm purely speculating because I don't know what those underlying searches look like.
Did you check the date and time of that event in comparison to the time you were searching for it?
Did you check whether the TZ and/or timestamp settings are correct for both the host you used the Eicar test file on, and the indexer?
I looked at the time chart dates and times in your picture, and compared that to the time you posted. It looks as if that event might have a time stamp in the future. Not sure what time zone you're in, but I've run into an issue before where an appliance had the incorrect system time set for events, and events were showing up in Splunk in the future. I also noticed something similar with my case that you also did; the events show up in a time chart, but not in a single value count or any adhoc search that specified a particular time range that wasn't all time.
If that isn't the case, I could take a look at the searches for you?
Those two indicators at the top look for 'action=allowed.' Your action is deferred so it does not match the search that the Key Indicators are looking for