In an advisory of its own, Cisco said the threat actors are compromising the devices after acquiring administrative credentials and that there’s no indication they are exploiting vulnerabilities.
If they aren’t exploiting vulnerabilities (and this is all because of mishandling of admin creds) then why are only Cisco routers being targeted?
They are loadi g in modified firmware apparently. Will be specific to Cisco hardware.
It's all kinda irrelevant though. If they managed to figure out your weak ass admin creds and you left your router open to access with no ACLs then installing some sneaky firmware is the least of your worries