alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE WEBC2-TABLE Checkin 1 - APT1 Related"; flow:established,to_server; flowbits:set,ET.webc2; http.header; content:"|3a|"; distance:1; within:1; content:"|3a|"; distance:2; within:1; content:"+"; distance:2; within:1; http.user_agent; content:"0"; startswith; reference:md5,7a7a46e8fbc25a624d58e897dee04ffa; reference:md5,110160e9d6e1483192653d4bfdcbb609; reference:url,www.mandiant.com/apt1; classtype:targeted-activity; sid:2016435; rev:7; metadata:created_at 2013_02_20, signature_severity Major, updated_at 2020_10_14;)