oherrala
I'd say return channel might work and it depends on the device used to exfiltrate out. In case of proper DNS server like Active Directory mentioned in the article it's likely that it could work. But we have not yet done testing.
We have also seen devices that are not DNS servers and still just forward broadcast packets from one network interface to another. In such case the return channel might not be possible.
The minimal effort included hours of studying electrical engineering and radio technology at university including all the math and physics needed. Studying for amateur radio license. And after founding this issue delving deep into radio interference literature and datasheets of various components. Then setting up a test environment to replicate the issue and do tests trying to eliminate the interference. After a success write a blog post describing the solution in short and hopefully interesting way.
Also if the interference didn't come from the disc side of charger then the issue wouldn't be resolved with ferrite bead on that end. If the issue was on the USB connector side then the bead should be placed there.
Eliminating Radio Interference from Apple Charger
Retired Server called Home – A server decommissioning failure
Survival Radio and Emergency Communications Ukraine [video]
OPNSense Firewall Bypass with Carp
Lopsided routing, a stealthy hole punch into FortiGate
Escaping from a truly air gapped network via Apple AWDL
Test for network leaks, discover a product flaw and get vendor to fix
Modern storage is plenty fast. It is the APIs that are bad
Bug in OpenSSH / Config Checker
Microsoft's Control Flow Guard for Clang/LLVM and Rust
Isolation Alloc – A security focused memory allocator
Kr00k vuln in WiFi chips that allows unauthorized decryption of traffic
Two-Line Element Set Checksum Controversy (1992)
The exe must have been running to be able to generate the proper encrypted payload and send it to right place. In this case ports 20 and 1025 over TCP.
Disclaimer: I am one of the people who wrote the software.
From https://www.openbsd.org/innovations.html:
> Library order randomization: In rc(8), re-link libc.so, libcrypto, and ld.so on startup, placing the objects in a random order. Theo de Raadt and Robert Peichaer, May 2016, enabled by default since OpenBSD 6.0 and 6.2.
and
> Kernel relinking at boot: the .o files of the kernel are relinked in random order from a link-kit, before every reboot. This provides substantial interior randomization in the kernel's text and data segments for layout and relative branches/calls. Basically a unique address space for each kernel boot, similar to the userland fork+exec model described above but for the kernel. Theo de Raadt, June 2017.