The Backdoor Factory allows you to patch binaries with combining that with mitmproxy, which will be a Python proxy-server that can capture HTTP, alter traffic on the fly render and decode primitive data types — gives you BDFProxy.

BDFProxy permits you to patch binaries through MiTM with The Backdoor Factory together with mitmproxy allowing on the fly patching of binary downloads (software updates by way of example) from vendors which don’t validate data integrity.
Only available at Darknet.