alert tcp any any -> $HOME_NET 1556 (msg:"ET EXPLOIT NB8-01 - Unauthed RCE via bprd"; flow:established,to_server; content:"ack="; depth:4; content:"extension=bprd"; distance:0; fast_pattern; pcre:"/^.*?[\x24\x60]/R"; reference:url,seclists.org/fulldisclosure/2017/May/27; classtype:web-application-attack; sid:2024308; rev:1; metadata:attack_target Server, created_at 2017_05_17, deployment Internal, performance_impact Moderate, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)