The backdoor affecting Sercomm wireless DSL routers has not been fixed, and lays hidden in the latest version of the devices` firmware to intercept users` home traffic. The number of devices affected is unknown, but manufacturers have not issued an official response. The backdoor can be reactivated through a network packet used by an old Sercomm update tool The packet`s payload is an MD5 hash of the router`s model number (DGN1000) Once the backdoor is turned back on, it monitors TCP/IP traffic and allows hackers to send commands to the router.”]
Source: https://www.bitdefender.com/blog/hotforsecurity/backdoor-still-hidden-in-patch-for-wi-fi-routers/