alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Gamaredon APT Style jpeg Request (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; pcre:"/^\/[a-z]{2}\/[^\r\n]+\/[0-9]{2}\.[0-9]{2}\//"; content:".jpeg"; endswith; fast_pattern; http.host; pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/"; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; reference:md5,a92c520c99b0c626b43ba4b3bd754ccc; classtype:bad-unknown; sid:2045046; rev:2; metadata:attack_target Client_Endpoint, created_at 2023_04_19, deployment Perimeter, performance_impact Significant, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_26; target:src_ip;)