alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Volt Typhoon User-Agent"; flow:established,to_server; http.user_agent; content:"Mozilla|2f|5|2e|0|20 28|Windows|20|NT|20|6|2e|1|3b 20|WOW64|3b 20|rv|3a|68|2e|0|29 09 09 09 20 20 20 20|Gecko|2f|20100101|20|Firefox|2f|68|2e|0"; reference:url,media.defense.gov/2023/May/24/2003229517/-1/-1/0/CSA_PRC_State_Sponsored_Cyber_Living_off_the_Land_v1.1.PDF; classtype:trojan-activity; sid:2048899; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_10_25, deployment Perimeter, deployment SSLDecrypt, malware_family Volt_Typhoon, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_10_25, reviewed_at 2023_10_25;)