If you already own ETS2 on Steam, here is the safe, legitimate method to play version 1.40:
In the dropdown menu labeled "Beta participation," look for temporary_1_40 - 1.40.x for outdated mods. Select it. ets2 1.40 product key
A: Contact SCS Software support. Very old pre-Steam keys (from 2012-2013) may need to be converted. Provide proof of purchase, and they often issue a Steam key. If you already own ETS2 on Steam, here