Security 3D Icons - Collection of 49 security icons.
Icons8 - Free app for Mac & Windows already containing 39,800 icons. Allows to search and import icons…
3dicons - 3dicons library offers beautifully designed open-source 3D icons.
Iconscout - Design Resource Marketplace.
Studyum 3D icons - 28 trendy customizable 3D icons for any e-learning product
Craftwork - A collection of User Interface resources made by Craftwork