alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Suspected USBFERRY CnC"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".6.jpg"; endswith; http.user_agent; content:"MSIE|28|6.00.2900.5512|20 28|"; fast_pattern; content:"|3b 20|NT|28|"; distance:0; content:"|29 3b 20|AV|28|"; distance:0; content:"|29 3b 20|OV|28|"; distance:0; content:"|29 3b 20|NA|28|"; distance:0; content:"VR|28|PH"; http.header_names; to_lowercase; content:!"|0d 0a|accept"; content:!"|0d 0a|referer|0d 0a|"; reference:url,documents.trendmicro.com/assets/Tech-Brief-Tropic-Trooper-s-Back-USBferry-Attack-Targets-Air-gapped-Environments.pdf; classtype:command-and-control; sid:2030169; rev:3; metadata:attack_target Client_Endpoint, created_at 2020_05_15, deployment Perimeter, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_05_04;)