The first one is the users default avatar and is supplied by the CB Bootstrap template. You can find it and its alternative image files below.
components/com_comprofiler/plugin/templates/bootstrap/images/avatar/
The other is GroupJives category icon, but this has been changed already in GJ 2.7. The Quickstart package from the Professional downloads section is out of date. I strongly encourage you to re-download and install it from our Package Builder found below (click Presets).
www.joomlapolis.com/downloads/cb-package-builder
Once up to date you'll find GJs icons at the below location.
components/com_comprofiler/plugin/user/plug_cbgroupjive/images/
Note for GJ you just need to add your new images to that folder and select it from within GJs backend configuration as the logos default.