alert http1 $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Qbot CnC Activity M3 (POST)"; flow:established,to_server; http.request_line; bsize:17; content:"POST|20|/t5|20|HTTP/1.1"; fast_pattern; http.accept; bsize:70; content:"application/x-shockwave-flash, image/gif, image/jpeg, image/pjpeg, */*"; http.request_body; pcre:"/^[A-Za-z0-9]{3,20}=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/si"; http.header_names; content:!"Referer"; reference:md5,da51dd657868bf4d2924b4398e045b27; classtype:command-and-control; sid:2038776; rev:3; metadata:attack_target Client_Endpoint, created_at 2022_09_08, deployment Perimeter, deployment SSLDecrypt, malware_family Qbot, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_03;)