doc88.com uses some kind of encryption to protect pdf files. I used Chrome developer tools and found that it loads .ebt file. I think its encrypted Pdf / Swf file.
I found the following reply Here but i still cannot download the pdf file. Can anyone help ?
Okay. The encryption that docin.com uses is absolutely unknown to me, but I determined that doc88.com probably uses software from cryptbot.com, through I was unable to extract the key: it's probably buried deep into the flash viewer. – whitequark