alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE APT/FamousSparrow Activity (POST)"; flow:established,to_server; urilen:1; http.method; content:"POST"; http.uri; content:"/"; http.host; content:"credits.offices-analytics.com"; bsize:29; fast_pattern; http.header_names; content:"|0d 0a|User-Agent|0d 0a|Accept-Language|0d 0a|Accept|0d 0a|Host|0d 0a|"; content:!"Referer"; reference:url,www.welivesecurity.com/2021/09/23/famoussparrow-suspicious-hotel-guest/; reference:url,twitter.com/ESETresearch/status/1441013111469879300; classtype:trojan-activity; sid:2034015; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_09_23, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_09_23;)