alert http $HOME_NET any -> $EXTERNAL_NET any (
msg:"ET MALWARE APT28 SEDNIT Variant CnC Beacon 2";
flow:to_server,established;
http.method;
content:"POST";
http.uri;
content:".zip/?"; fast_pattern;
pcre:"/\.zip\/\?[A-Za-z0-9]+=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/";
http.header_names;
content:!"Content-Type|0d 0a|";
content:!"Accept";
content:!"Referer|0d 0a|";
reference:md5,c2988e3e4f70d5901b234ff1c1363dcc;
classtype:targeted-activity;
sid:2023913; rev:4;
metadata:attack_target Client_Endpoint, created_at 2016_06_09, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_10_06, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)