New Whitepaper: Stealthy BPFDoor Variants are a Needle That Looks Like Hay The article analyzes BPFDoor-derived implants (icmpShell/httpShell and multiple Rapid7 variants) that use custom BPF filters, protocol sniffing, and protocol-tunneling C2 to achieve stealthy remote shells and persistence. It highlights key artifacts such as the RC4 key "icmp", hardcoded ICMP Sequence Number 1234, and active beaconing domains that masquerade as NTP-over-SSL. #BPFDoor #icmpShell

New whitepaper reveals stealthy BPFDoor variants using custom BPF filters, ICMP PTY tunnels with RC4 key “icmp”, and NTP-over-SSL beaconing domains for covert C2 and persistence. #BPFDoor #ProtocolTunneling #UnitedStates