ET HUNTING bmp File Request Returning Encoded File

Query · suricata

flow:established,to_client;
flowbits:isset,ET.bmp_seen;
http.stat_code;
content:"200";
http.content_type;
content:"image/bmp";
http.content_len;
byte_test:0,>,450000,0,string,dec;
file.data;
content:"=="; startswith; fast_pattern;
pcre:"/^[A-Za-z0-9+/]{180}/R";
target:dest_ip;

Rule dependencies

⚠ Higher-order rule. It fires on other rules' alerts, not on raw events, so it cannot fire on its own. Deploy the rules it depends on too.

Depends on

Raw source ET HUNTING bmp File Request Returning Encoded File · Suricata
Esc
Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged. 
alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"ET HUNTING bmp File Request Returning Encoded File";
    flow:established,to_client;
    flowbits:isset,ET.bmp_seen;
    http.stat_code;
    content:"200";
    http.content_type;
    content:"image/bmp";
    http.content_len;
    byte_test:0,>,450000,0,string,dec;
    file.data;
    content:"=="; startswith; fast_pattern;
    pcre:"/^[A-Za-z0-9+/]{180}/R";
    classtype:bad-unknown;
    sid:2050073; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2024_01_16, deployment Perimeter, performance_impact Low, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_01_16;
    target:dest_ip;
)

Detection rules belong to the projects that publish them and remain under their own licenses. This site indexes and links to them; it claims no rights in them.