alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE OILRIG CnC POST"; flow:established,to_server; content:"|3a 20|chrome|0d 0a|"; fast_pattern; http.method; content:"POST"; http.uri; content:"/?v="; startswith; http.header_names; content:"From|0d 0a|User-Agent|0d 0a|"; content:!"Referer"; http.user_agent; content:"chrome"; bsize:6; reference:url,unit42.paloaltonetworks.com/oilrig-novel-c2-channel-steganography/; reference:md5,acaff6cb817399848887caef0104bd03; classtype:command-and-control; sid:2030634; rev:2; metadata:attack_target Client_Endpoint, created_at 2020_07_30, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_07_31;)