Constant "Infection Blocked" notices

[REDACTED]

I've started getting 6 constant notices of Infection Blocked notices. 

*******
Infection blocked!
Avast Filesystem shield has blocked a threat and moved it to the Chest.

Infectin: Win32:OutBrowse-G [PUP]
User:      Pegs
Process:  /Applications/Dropbox.app/Contents/MacOS/Dropbox109
File:        /Users/Pegs/Dropbox/.dropbox.cache/-6486d5b33.tmp

*******

I'm getting 6 popups like this for 6 different files.

I have no idea what to do with them.  Appreciate any help.

PegM

[Milos]

Hello,
PUP = Potentially Unwanted Program, mostly bundled toolbars/adware in some installers. If you want it, just disable PUPs in settings.

Milos