alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/StreamFlaw.A Checkin"; flow:established,to_server; urilen:1; http.method; content:"POST"; http.user_agent; content:"Mozilla/6.0 (compatible|3b 20|MSIE 6.0"; fast_pattern; startswith; http.header_names; content:!"Referer|0d 0a|"; reference:md5,981672cd969fe8cb1f887d0526b1ecf2; classtype:command-and-control; sid:2020947; rev:4; metadata:created_at 2015_04_18, malware_family Win32_StreamFlaw_A, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_06_04;)