alert dns $HOME_NET any -> any any (
msg:"ET MALWARE Pupy DNS Request without SPI M3";
dns.query; bsize:>42;
content:"999."; fast_pattern; offset:29; depth:28;
content:"9."; within:57;
content:"."; distance:0;
pcre:"/^(?:[a-z0-8\-]{8}){3,7}[a-z0-8\-]{5}9{3}\.(?:[a-z0-8\-]{8}){1,7}(?:[a-z0-8\-]{2}9{6}|[a-z0-8\-]{4}9{4}|[a-z0-8\-]{5}9{3}|[a-z0-8\-]{7}9)?\./";
reference:url,insights.infoblox.com/resources-whitepaper/infoblox-whitepaper-decoy-dog-is-no-ordinary-pupy-distinguishing-malware-via-dns;
classtype:command-and-control;
sid:2046964; rev:1;
metadata:attack_target Client_Endpoint, created_at 2023_07_31, deployment Perimeter, deployment Internal, malware_family PupyRat, performance_impact Moderate, confidence Medium, signature_severity Critical, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_07_31;
target:src_ip;
)