alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Kimsuky Related Host Data Exfil M3"; flow:established,to_server; http.uri; pcre:"/^\/\?m=[abcde]&p1=[a-f0-9]{8,12}(?:&p2=[^&]+)?(?:&p3=[^&]+)?$/i"; http.uri.raw; content:"//?m="; startswith; fast_pattern; content:"&p1="; distance:1; within:4; http.header_names; to_lowercase; content:!"|0d 0a|content-type|0d 0a|"; reference:md5,1e14ded758c5dd7b41fe20297935eeef; classtype:targeted-activity; sid:2035444; rev:5; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_06_18, deployment Perimeter, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_05_01;)