alert http1 $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Zeus Checkin Header Pattern"; flow:established,to_server; http.method; content:"POST"; nocase; http.protocol; content:"HTTP/1.1"; http.accept; content:"*/*"; http.header; pcre:"/^X-ID\x3a\x20\d+\r?$/m"; http.header_names; content:"|0d 0a|Accept|0d 0a|X-ID|0d 0a|"; fast_pattern; classtype:command-and-control; sid:2014014; rev:9; metadata:created_at 2011_12_09, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_08;)