The backdoor implanted on Cisco devices by exploiting a pair of zero-day flaws in IOS XE software has been modified by the threat actor so as to escape visibility via previous fingerprinting methods.
“Investigated network traffic to a compromised device has shown that the threat actor has upgraded the implant to do an extra header check,” NCC Group’s Fox-IT team said. “Thus, for a lot of devices, the implant is still active, but now only responds if the correct Authorization HTTP header is set.”
