The FBI recommends a factory reset for affected routers. I wasn't sure if Sagemcom might be a re-branded device or not. From what I can tell online it seems not, I'm just trying to be diligent on this.
I was curious about this too. There is a consistency of service that is apparent. This would have been a great place to pin a post about this.
There is already a thread on this subject running in the INTERNET > Connectivity sub-topic VPNFilter - Arris TG1672 . To date nobody has posted a problem with their Spectrum rented router devices here in the Forums that was identifiable as 'VPNFilter'.
List of affected routers:
Mikrotik RouterOS for Cloud Core Routers: Versions 1016, 1036, and 1072
QNAP TS439 Pro
Other QNAP NAS devices running QTS software