ET MALWARE Cobalt Strike Malleable C2 Profile (extension.css)

Query · suricata

flow:established,to_server;
http.uri;
content:"/extension.css?goto="; startswith;
http.cookie;
content:"lu="; startswith; fast_pattern;
http.header_names;
content:!"Referer";
Raw source ET MALWARE Cobalt Strike Malleable C2 Profile (extension.css) · 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 Cobalt Strike Malleable C2 Profile (extension.css)";
    flow:established,to_server;
    http.uri;
    content:"/extension.css?goto="; startswith;
    http.cookie;
    content:"lu="; startswith; fast_pattern;
    http.header_names;
    content:!"Referer";
    reference:url,twitter.com/Unit42_Intel/status/1387149833274810368;
    reference:url,github.com/pan-unit42/tweets/blob/master/2021-04-26-IcedID-with-Cobalt-Strike-IOCs.txt;
    classtype:trojan-activity;
    sid:2033148; rev:1;
    metadata:attack_target Client_Endpoint, created_at 2021_06_17, deployment Perimeter, malware_family Cobalt_Strike, confidence Medium, signature_severity Major, updated_at 2021_06_17, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;
)

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.