Blog post got hacked

Well you see, I have not been writing into this for a while-- about a year or so. What happened one day when I decided to login and checked, I discovered someone been posting into my blog and there were 200 over posts. I checked my google account, it has not been compromised. Also, I have started using the two way authenticated method and mobile text verification. It is kinda of secure I thought.

I suppose one way these guys manage to post into my blog was I have enabled the mobile blogging.

To disable, click settings --> Mobile and Email ==> Posting via email. Checked on "disabled".

I hope this shut the fellow out there.