I have managed to send a longer string as a TCP packet with nping.
0000 d0 50 99 0d ab 0f 00 0c 29 6f 3b 80 08 00 45 00 ÐP..«...)o;...E. 0010 00 e3 07 90 00 00 40 06 ef 2b c0 a8 01 04 c0 a8 .ã....@.ï+À¨..À¨ 0020 01 05 27 ff 01 bb 29 fa 38 90 00 00 00 00 50 02 ..'ÿ.»)ú8.....P. 0030 05 c8 0e 01 00 00 48 65 6c 6c 6f 20 57 6f 72 6c .È....Hello Worl 0040 64 2e 20 54 68 69 73 20 69 73 20 61 20 63 75 73 d. This is a cus 0050 74 6f 6d 20 49 43 4d 50 20 70 61 63 6b 65 74 2e tom SYN packet. 0060 20 49 20 6c 6f 76 65 20 73 65 6e 64 69 6e 67 20 I love sending 0070 74 68 69 73 20 73 74 75 66 66 2e 20 59 6f 75 20 this stuff. You 0080 63 61 6e 20 75 73 65 20 61 20 6c 6f 6e 67 20 73 can use a long s 0090 74 72 69 6e 67 20 61 73 20 77 65 6c 6c 2e 20 56 tring as well. V 00a0 65 72 79 20 6c 6f 6e 67 20 69 6e 64 65 65 64 2e ery long indeed. 00b0 20 53 6f 20 6c 6f 6e 67 2c 20 69 74 20 62 6c 6f So long, it blo 00c0 61 74 73 20 74 68 65 20 70 61 63 6b 65 74 20 71 ats the packet q 00d0 75 69 74 65 20 61 20 62 69 74 2c 20 62 75 74 20 uite a bit, but 00e0 73 74 69 6c 6c 20 77 6f 72 6b 73 20 66 69 6e 65 still works fine 00f0 2e . |
Packet summary.
7147 288.878742 192.168.1.4 192.168.1.5 TCP 241 10239 → 443 [SYN] Seq=0 Win=1480 Len=187 |
This was sent using nping, that comes with the nmap package on Linux. This allows sending custom TCP packets as a ping request to a remote machine, that may be captured with tcpdump or Wireshark. But if the packet is sent over SSH, it is encrypted and does not work well as a medium for sending a message. This could possibly be used to send a message, if the parts of the file were placed in the packets and then extracted and reassembled at the destination machine. Very interesting indeed.
This is the command I used to send this large network packet.
jason@hoshi:~$ sudo nping -c 1 --data-string "Hello World. This is a custom ICMP packet. I love sending this stuff. You can use a long string as well. Very long indeed. So long, it bloats the packet quite a bit, but still works fine." --tcp -p 80,443 192.168.1.2 |
This is a fun thing to try, it is up to you what you send as a message, even a small file would work.