alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE MirrorBlast KiXtart Downloader Client Request"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".php?data="; fast_pattern; pcre:"/(?:fCxTeXN0ZW0gSWRsZS|wsU3lzdGVtIElkbGUg|8LFN5c3RlbSBJZGxlI)/R"; http.header_names; content:!"|0d 0a|Referer|0d 0a|"; reference:md5,254022730f51ee770452015b6987b939; reference:url,twitter.com/rcwht_/status/1443867650686439489; classtype:command-and-control; sid:2034091; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_10_01, deployment Perimeter, malware_family MirrorBlast, performance_impact Moderate, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_10_04;)