Found in tcp stream 5, packet 827 (the first unencrypted stream)
Gur synt vf cvpbPGS{c33xno00_1_f33_h_qrnqorrs}
Seems flaglike, maybe rot13 to protect against text search?
Output from cyberchef:
The flag is picoCTF{p33kab00_1_s33_u_deadbeef}