I could write a book on Acronis. If it is working correctly, then it is awesome. You are a much smarter man than I, if you set it up.
I have two Buffalo NASs and one automatically backs up to the other. But, yes, I could possibly see having the CryptoLocker on your server and not knowing after hours (for some reason you do something on the server) and the nightly backup backs it up. That backup is no good even though the removal of the CL is simple. But, the backup from the day before would only be encrypted if you didn't notice a problem the entire next day.
I have to admit, I went out and paid over $200 to get MBAM pro which can run real time next to your A/V. Don't worry so much about scans, but having real time scanning and just detection.
We have the best and the worst. We have info that is sacred, but we also have info that no hacker wants. They want bank statements, credit card date, etc.
I love little sayings that have a ton of meeting. I was on EE once and asked a question about hackers. And, the expert said:
Can a hacker get into your server? Definitely, no matter how secure.
Does a hacker want to get into YOUR server. Probably not.