[Chepy](https://github.com/securisec/chepy)
```from chepy import Chepy
c = Chepy("loopback.pcap")
flag = (    # read pcap    c.read_pcap()    # extract all ICMP payloads    .pcap_payload("ICMP")    # Because payloads repeat, extract only one    .select_every_n(2)    # pull the 16th byte of each payload which also repeats    .loop_list("slice", {"start": 16, "end": 17})    # join payload to form PNG file    .join_list(b"")    # extract binary strings    .extract_strings()    # extract flag    .search_ctf_flags(prefix="LLS"))print(flag)```