alert http1 $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/ViperSoftX Stealer Activity M3 (POST)"; flow:established,to_server; http.request_line; content:"POST /connect HTTP/1.1"; http.header; content:"X-User-Agent|3a 20|"; fast_pattern; pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})\r\n/R"; http.header_names; bsize:52; content:"|0d 0a|X-User-Agent|0d 0a|Host|0d 0a|Content-Length|0d 0a|Connection|0d 0a 0d 0a|"; reference:url,decoded.avast.io/janrubin/vipersoftx-hiding-in-system-logs-and-spreading-venomsoftx/; reference:md5,d8f4fde20adbf45cff5c5413ef4b855d; classtype:trojan-activity; sid:2040139; rev:3; metadata:attack_target Client_Endpoint, created_at 2022_11_28, deployment Perimeter, malware_family ViperSoftX, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_03; target:src_ip;)