ET EXPLOIT Possible Malicious x-sharing-config-url SMTP header observed (CVE-2023-35636)

alert smtp any any -> $HOME_NET any (
    msg:"ET EXPLOIT Possible Malicious x-sharing-config-url SMTP header observed (CVE-2023-35636)";
    flow:established,to_server;
    content:"Content-Class|3a 20|Sharing"; nocase;
    content:"x-sharing-config-url|3a 20|\\"; fast_pattern; nocase;
    content:".ics"; within:50;
    reference:url,www.varonis.com/blog/outlook-vulnerability-new-ways-to-leak-ntlm-hashes;
    reference:cve,2023-35636;
    classtype:credential-theft;
    sid:2050433; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_Endpoint, created_at 2024_01_24, cve CVE_2023_35636, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence Low, signature_severity Major, updated_at 2024_01_24;
    target:dest_ip;
)