Powershell - Fileless Malware

Several times a day I’m getting the following notice:

We’ve moved the threat powershell.exe to your virus chest

Looking at details I get:

Threat Name: IDP.HELU>PSE13 - Fileless malware
Process: [drive letter]\System32\WindowsPowerShell\V1.0\powershell.exe
Detected by: Behavior Shield
Status: Move to Virus Chest

Look in the Virus Chest and there’s no files in there.

This has been going on for a couple weeks now and I’ve run many antivirus, malware, and PUP checkers above and beyond Avast… and nothing, not a single one of them, finds a thing.

So… help please… this is driving me nuts.

Attach your basic diagnostic logs. (MBAM and FRST)
Instructions: https://forum.avast.com/index.php?topic=194892

Can you upload the file to www.virustotal.com too? (and post the scan result here please.)