Well that is pretty much the same message I got, but Firefox got there first.
What browser are you using ?
What avast free version 21.11.2500 (build 21.11.6809.528) what version are you using ?
I'm fairly sure if Firefox hadn't blocked it I would have got the same alert from Avast.
The thing is that I get it on the huawai.com site I'm not trying to access twitter. So I can only assume that there is some related huawai content being accessed in twitter.