alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE APT Mustang Panda CnC Activity"; flow:established,to_server; content:".dat HTTP/1.1|0d 0a|User-Agent|3a 20|Microsoft Internet Explorer|0d 0a|"; fast_pattern; http.method; content:"GET"; http.header_names; content:!"Referer"; content:!"Accept-"; reference:url,go.recordedfuture.com/hubfs/reports/cta-2020-0728.pdf; reference:md5,2ec79d0605a4756f4732aba16ef41b22; classtype:command-and-control; sid:2030671; rev:1; metadata:attack_target Client_Endpoint, created_at 2020_08_10, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag MustangPanda, tag TA416, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_10;)