Weird behavior

The challenge starts with a .pcapng file and the following text

Exersand pe robot noul modul esp8226 pentru comunicatii TCP/IP am observat ca acesta incepe sa faca request-uri unintended. Poti sa verifici captura te rog?

Practicing on the robot the new esp8226 module for TCP/IP communications I noticed that it is starting to make unintended requests. Can you check the capture please?

After opening the file in Wireshark we see a lot of traffic. Filtering the traffic for HTTP requests we see a single request. Looking at the response we can see the flag in plain text.

<script>
    document.cookie = "congrats=NOFB-PGS{1xq2!(pZQP21yQ19K5(@04ZqPX1wxp21,1P4}";
    document.addEventListener("keydown", (e) => {
        if (e.ctrlKey || e.keyCode==123) {
            e.stopPropagation();
            e.preventDefault(); 
        }
    });
</script>
<img src="https://ahseeit.com//king-include/uploads/2021/07/thumb_4ce8c60a1c33660bf89eb086d66c289148b6ad08fd1f11ea0fd397ecb3a15290-6765237721.jpg" style="width:420px;height:400px;"></img>

Decoding the flag from document.cookie using rot13, we get the flag: ABSO-CTF{1kd2!(cMDC21lD19X5(@04MdCK1jkc21,1C4}