ET MALWARE SiameseKitten/Lyceum/Hexane MSIL/Shark Uploading to CnC

Query · suricata

flow:established,to_server;
http.method;
content:"POST";
http.uri;
content:"?q=";
content:"o543n"; endswith; fast_pattern;
http.user_agent;
content:"|28|Windows|20|NT|20|10.0|3b 20|Win64|3b 20|x64|29|";
http.request_body;
content:"|7b 22|Data|22 3a 5b 22|"; startswith;
pcre:"/^(?:[A-Z0-9+/]{4})*(?:[A-Z0-9+/]{2}==|[A-Z0-9+/]{3}=|[A-Z0-9+/]{4})/R";
content:"|22 5d 7d|";
Raw source ET MALWARE SiameseKitten/Lyceum/Hexane MSIL/Shark Uploading to CnC · Suricata
Esc
Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged. 
alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE SiameseKitten/Lyceum/Hexane MSIL/Shark Uploading to CnC";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:"?q=";
    content:"o543n"; endswith; fast_pattern;
    http.user_agent;
    content:"|28|Windows|20|NT|20|10.0|3b 20|Win64|3b 20|x64|29|";
    http.request_body;
    content:"|7b 22|Data|22 3a 5b 22|"; startswith;
    pcre:"/^(?:[A-Z0-9+/]{4})*(?:[A-Z0-9+/]{2}==|[A-Z0-9+/]{3}=|[A-Z0-9+/]{4})/R";
    content:"|22 5d 7d|";
    classtype:command-and-control;
    sid:2033762; rev:1;
    metadata:created_at 2021_08_22, malware_family Shark, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_08_22;
)

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