ET MALWARE [ANY.RUN] Win32/ObserverStealer CnC Activity (Loading) M2

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE [ANY.RUN] Win32/ObserverStealer CnC Activity (Loading) M2";
    flow:established, to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/s?id="; startswith; fast_pattern;
    pcre:"/^\/s\x3fid\x3d([0-9a-f]{8})-([0-9a-f]{4})-([0-9a-f]{4})-([0-9a-f]{4})-([0-9a-f]{12})$/";
    http.host;
    pcre:"/^(?:(?:\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.){3}(?:\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])(:\d{2,5})?$/R";
    http.accept;
    content:"|2a 2f 2a|"; bsize:3;
    http.accept_enc;
    content:"gzip|2c 20|deflate"; bsize:13;
    http.connection;
    content:"Keep-Alive"; bsize:10;
    http.user_agent;
    content:".NET";
    http.header_names;
    content:"Accept|0d 0a|Accept-Encoding|0d 0a|User-Agent|0d 0a|Host|0d 0a|Connection|0d 0a 0d 0a|"; bsize:59;
    reference:md5,c28cc92a7c78b96bec58fa3e5398074a;
    reference:url,community.emergingthreats.net/t/observerstealer/624;
    reference:url,app.any.run/tasks/5728c30e-00c1-4f87-9522-ff8b9e08fa32/;
    classtype:trojan-activity;
    sid:2046170; rev:2;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_06_07, deployment Perimeter, malware_family ObserverStealer, confidence High, signature_severity Critical, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_06_23, reviewed_at 2024_01_26;
)