Beware of the fake steam voucher site ‘steamvoucherverification.com’, this site has been setup with just one main focus: to get credentials/vouchers of steam players.
‘steamvoucherverification.com’
The first thing that pop-ups is that the site makes no use of any type of traffic encryption.

Once you start pressing on some links, you will also notice, that the link will redirect you to clear .html sites.

The website does seem to have used Let’s Encrypt in the past. So the chance is there that it will utilize HTTPs in the near future again.
Where does it try to steal vouchers?
On the page, there is a frame where you can provide vouchers and the email id.

Malicious site info:
https://steamvoucherverification.com/ http://steamvoucherverification.com/ https://steamvoucherverification.com/index-2.html http://steamvoucherverification.com/index-2.html Destination IP: 85.187.128.7