pscp_300.dll is part of virtual CNC. Virtual CNC, a 3D machine simulation and verification for 2-5 Axis Mills, lathes, mill/turns, lasers, waterjets and routers.
Surfcam also need this file. SURFCAM is CAD CAM software for 3D milling, mill turn, multi axis machining and 3D machining amongst other unique features. Surfcam protected 11 files include : cat2dsn.dll, dsn2igs.dll, Dsnfix.dll, PEditorSimLibrary.dll, prsd2dsn.dll, pscp_300.dll, sat2dsn.dll, Spostg.exe, Spostl.exe, Spostm.exe and Sx32w.dll .
pscp_300.dll is safe if you installed software related to 3D.