it sounds to me like the page isn't using https (note the S on the end there.) the https protocol (plain http won't.) will encrypt data sent to the server, so it is considered secure, within reason.
The login link should look something like this:
https://feral-heart.com/login/index.php (note the https here!)
if it still isn't using https, then I suspect some sort of browser incompatibility. Perhaps you should try another one? =3
Also as a side note, in my opinion antivirus typically makes you less secure since it increases the attack surface, for they are susceptible to bugs like any software out there (maybe even moreso!).
