alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Minimal Header Github Request for PNG File"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".png"; endswith; http.host; content:"github.com"; endswith; fast_pattern; http.connection; content:"Keep-Alive"; http.header_names; bsize:<30; content:!"|0d 0a|user-agent|0d 0a|"; nocase; content:!"|0d 0a|referer|0d 0a|"; nocase; content:!"|0d 0a|accept|0d 0a|"; nocase; content:!"|0d 0a|x-auth|0d 0a|"; nocase; content:!"|0d 0a|cookie|0d 0a|"; nocase; reference:md5,bedd7b113e7db2fc8fb91c74089b9c27; classtype:misc-activity; sid:2064697; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Mac_OSX, affected_product Linux, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2025_09_15, deployment Perimeter, deployment SSLDecrypt, performance_impact Significant, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_09_15; target:src_ip;)