alert http $HOME_NET any -> $EXTERNAL_NET !80 (
msg:"ET MALWARE PurpleFox Backdoor/Rootkit Download Request M2";
flow:established,to_server;
http.method;
content:"GET";
http.uri;
content:"/"; startswith;
content:".zip?="; within:7; fast_pattern;
pcre:"/^(?:0|1[678]\d{8})$/R";
http.host;
pcre:"/^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$/";
http.header_names;
content:"|0d 0a|Accept|0d 0a|"; startswith;
content:"Accept-Encoding|0d 0a|User-Agent|0d 0a|Host|0d 0a|Connection|0d 0a|";
reference:url,blog.minerva-labs.com/malicious-telegram-installer-drops-purple-fox-rootkit;
reference:md5,465dae978a41d566c7fabc9f5808487c;
classtype:command-and-control;
sid:2034871; rev:1;
metadata:attack_target Client_Endpoint, created_at 2022_01_07, deployment Perimeter, malware_family PurpleFox, performance_impact Moderate, confidence High, signature_severity Major, updated_at 2022_01_07;
)