The IP address is either blacklisted or there is somehow a conflict between the two products resulting in Malwarebytes blocking it (I highly doubt this is the case and believe it's the first one). False Positives are possible but if it was blacklisted then Malwarebytes must have had a reason to do this.
You can contact Malwarebytes for support about this issue here and see what they do:
https://www.malwarebytes.org/support/
Personally aside from this issue, I recommend against using Baidu. I recommend you use Avira Free Antivirus instead:
http://www.avira.com/en/avira-free-antivirus - of course should you like Baidu and wish to keep it then feel free to do so, but my advice would be to remove it in exchange for Avira Free Antivirus.
Regardless of whether Baidu has the option to enable the Avira engine, this does not mean it will have all of the Avira detection necessarily. I think you will be better off with Avira Free (unless you wish to purchase Avira Antivirus Pro, in which if you were purchasing a product over using a Free one I would recommend a different product).
Cheers.