ET HUNTING Suspicious Base64 Encoded ZIP File in HTML Body (Magic Bytes)

alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"ET HUNTING Suspicious Base64 Encoded ZIP File in HTML Body (Magic Bytes)";
    flow:established,to_client;
    file_data;
    content:"data|3a|"; nocase;
    content:"base64,UEsDB"; within:60; fast_pattern;
    flowbits:set,et.exploitkitlanding;
    reference:url,urlscan.io/result/98d7e72b-67b8-4d7c-9735-c27525b0a550/#transactions;
    classtype:misc-activity;
    sid:2019324; rev:5;
    metadata:attack_target Client_Endpoint, created_at 2014_09_30, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Informational, tag HTML_Smuggling, updated_at 2023_10_06, reviewed_at 2023_08_28, mitre_tactic_id TA0005, mitre_tactic_name Defense_Evasion, mitre_technique_id T1027, mitre_technique_name Obfuscated_Files_or_Information;
    target:src_ip;
)