It is possible. A password can be reset even when you have forgotten it. Read Mr. Waseem’s answer and try that. However, it can be more complicated. Several years ago I was hacked through eBay. I ended up having to call Apple to get it corrected. Ultimately, it is similar to forgetting a password, but more complicated. Apple was helpful. T asked random questions for which I had ready answers. It was clear that I was the owner of the account. It was helpful that I was an early adopter of .mac and had a transparent history.
If you do want to have your iCloud data backed up, Apple's support service should be able to provide that. What is it that needs to be backed up? I was using iCloud because I got that iCloud security feature for no particular reason beyond the usual “it's free”. After an attack has been reported on your account, no one is likely to want to back things up. I was a victim when somebody else hacked into my iCloud account and got my photos. The FBI has used the iCloud accounts of at least twenty victims to back-do’t the San Bernardino attack, using the Apple ID kings to get photos. Apple's iPhone 6 and 6 Plus are not encrypted when the password is on the phone; the encryption key on the phone is stored on the server and can be accessed. And this is exactly what the NSA wants. They want.