alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE IsSpace/Zacom Connectivity Check"; flow:established,to_server; urilen:1; http.method; content:"GET"; http.host; bsize:17; content:"www.microsoft.com"; http.user_agent; content:"Mozilla/5.0 (compatible|3b 20|MSIE 7.0|3b|Windows NT 5.1)"; fast_pattern; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; reference:md5,25631f5ccec8f155a8760b8568ca22c5; classtype:trojan-activity; sid:2021215; rev:5; metadata:created_at 2015_06_09, signature_severity Major, updated_at 2024_04_29;)