alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE APT Hellsing Proxy Checker Checkin"; flow:established,to_server; http.uri; content:"/common.asp?action="; content:"&uid="; distance:0; content:"&lan="; distance:0; content:"&hname="; distance:7; within:22; content:"&uname="; distance:1; within:22; content:"&os="; distance:0; http.header_names; content:!"Referer|0d 0a|"; reference:md5,b7e7186d962d562af6a5d10a25d19b02; reference:url,securelist.com/analysis/publications/69567/the-chronicles-of-the-hellsing-apt-the-empire-strikes-back/; classtype:targeted-activity; sid:2021108; rev:4; metadata:created_at 2015_05_15, signature_severity Major, updated_at 2020_05_22;)