**
Ironically, you can use Microsoft’s current tooling to create the offline installer yourself. This is the only official way to guarantee you are getting genuine, unmodified bits from Microsoft. visual studio 2012 update 3 offline installer download
vs2012.3_ult_enu_web.exe /layout "C:\VS2012_Offline" ** Ironically, you can use Microsoft’s current tooling
Once finished, navigate to C:\VS2012_Offline . You should see vs_setup.exe , a packages folder, and a Certificates folder. This is your offline installer. a packages folder
If you need the exact SHA-1 hash to verify a downloaded ISO, let me know.
100% safe and official. Cons: You still need an internet connection for the initial download.