alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Maldoc Activity (set)"; flow:established,to_server; flowbits:set,ET.maldoc.trick; flowbits:noalert; http.method; content:"GET"; http.uri; content:".png"; endswith; fast_pattern; http.header_names; content:"|0d 0a|Host|0d 0a|"; content:"|0d 0a|Connection|0d 0a|"; bsize:22; http.host; pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/"; reference:md5,e6258c27362df0668295258b69a5a74d; classtype:trojan-activity; sid:2034631; rev:2; metadata:attack_target Client_Endpoint, created_at 2021_12_08, deployment Perimeter, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_03_20;)