CM600 possible faulty firmware update?

[bubujove]

Back in July, my internet usage at home spiked to from a typical 200 GB per month to 1.2 TB (resulting in fees) with no change in usage. I contacted my ISP (Xfinity) and they said it could be a faulty firmware update for my CM600 modem and that I should reach out to the manufacturer to determine if there was a firmware update in July that could have caused the spike.

How do I check on my own whether the device has been updated? Is it possible to see a log file on the modem?

If I can show that it was not the modem, I can have Xfinity open an investigation to figure out the cause.

[plemans]

No. 

A faulty modem isn't going to cause it. 

From my experience, its usually either someone watching something, a program that's running in the background on a computer, or even a virus. I got hit with a miner once that chewed through 600gb in just a couple days. 

[bubujove]

Thanks for your reply.

Are you saying that it is not possible for a faulty firmware update to make repeated requests in error or are you saying that it is not possible to see logs from the modem?

While I certainly believe that it is not the modem, I would like to be able to check and verfiy. I would like to know
1) was a firmware update issued (where can I find this information)?
2) are there logs I can see on the modem itself?
3) do these modems automatically update themselves? I think there is a good chance that they do not, but, again, I don’t know. Xfinity may simply be mistaken in believing that the modem I am using is one of their own.

Thanks for your help.

[plemans]

The firmware is part of the provisioning from the ISP. The ISP pushes any firmware/updates automatically. 

Not saying it can't be bad (see the CAX30 fiasco) but its pretty thoroughly tested. 

And not saying something internally can't be wrong in the modem. Thats always a potential. it's just not something that I've seen on here and I've been on here a while. It tends to be something else causing increased data usage.