ET INFO Empty POST with Terse Headers Over Non Standard Port

Query · suricata

flow:established,to_server;
http.request_line;
content:"POST / HTTP/1.1";
http.header_names;
content:"|0d 0a|Host|0d 0a|Content-Length|0d 0a 0d 0a|"; bsize:26;
http.host;
pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/";
http.content_len;
byte_test:0,=,0,0,string,dec;
Raw source ET INFO Empty POST with Terse Headers Over Non Standard Port · 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 -> $EXTERNAL_NET 1024: (
    msg:"ET INFO Empty POST with Terse Headers Over Non Standard Port";
    flow:established,to_server;
    http.request_line;
    content:"POST / HTTP/1.1";
    http.header_names;
    content:"|0d 0a|Host|0d 0a|Content-Length|0d 0a 0d 0a|"; bsize:26;
    http.host;
    pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/";
    http.content_len;
    byte_test:0,=,0,0,string,dec;
    reference:url,twitter.com/3xp0rtblog/status/1509267848958562305;
    reference:md5,52a46f058ec6b726fe2829a590a15155;
    classtype:bad-unknown;
    sid:2036225; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2022_04_14, deployment Perimeter, performance_impact Moderate, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_04_14, reviewed_at 2023_09_01;
)

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