alert http $HOME_NET any -> $EXTERNAL_NET any (
msg:"ET MALWARE W32/Threebyte.APT Checkin";
flow:established,to_server;
http.method;
content:"GET";
http.uri;
content:"/UID"; fast_pattern; depth:4;
content:".jsp?"; distance:0;
pcre:"/^\/UID\d+\.jsp\?/";
http.header_names;
content:!"Accept";
content:!"Referer|0d 0a|";
reference:url,fireeye.com/blog/technical/botnet-activities-research/2014/09/darwins-favorite-apt-group-2.html;
classtype:targeted-activity;
sid:2019114; rev:3;
metadata:created_at 2014_09_04, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_05_04;
)