alert http $HOME_NET any -> $EXTERNAL_NET any (
msg:"ET MALWARE BBSRAT GET request CnC";
flow:to_server,established;
http.method;
content:"GET";
http.uri;
content:"/bbs/"; depth:5; fast_pattern;
content:"/forum.php?sid="; distance:0;
pcre:"/^\/bbs\/(?P<counter>[a-f0-9]+)\/forum\.php\?sid=(?P=counter)$/i";
http.user_agent;
content:"Mozilla/4.0 (compatible|3b 20|Windows NT 5.1)"; startswith;
http.cookie;
pcre:"/[A-F0-9]{8}(?:-[A-F0-9]{4}){2}-[A-F0-9]{8}/";
reference:md5,8cd233d3f226cb1bf6bf15aca52e0e36;
reference:url,researchcenter.paloaltonetworks.com/2015/12/bbsrat-attacks-targeting-russian-organizations-linked-to-roaming-tiger/;
classtype:command-and-control;
sid:2022310; rev:3;
metadata:created_at 2015_12_24, signature_severity Major, updated_at 2020_06_16;
)