ET EXPLOIT Possible Google Cookie Token Manipulation Activity

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET EXPLOIT Possible Google Cookie Token Manipulation Activity";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:"/oauth/multilogin"; startswith;
    http.host;
    content:"accounts.google.com"; bsize:19; fast_pattern;
    http.content_type;
    content:"application/x-www-form-urlencoded"; bsize:33;
    http.header;
    content:"Authorization|3a 20|MultiBearer|20|";
    http.header_names;
    content:"|0d 0a|Accept|0d 0a|";
    content:!"Referer";
    reference:url,www.cloudsek.com/blog/compromising-google-accounts-malwares-exploiting-undocumented-oauth2-functionality-for-session-hijacking;
    reference:url,medium.com/@DeputyDog/breaking-through-the-infostealer-exploit-and-the-enigma-of-cookie-restoration-e03e6e3cda50;
    classtype:attempted-admin;
    sid:2049906; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2024_01_04, deployment Perimeter, deployment SSLDecrypt, confidence Low, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_01_04;
    target:src_ip;
)