alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Malgent!MSR User-Agent"; flow:established,to_server; http.user_agent; bsize:22; content:"Not a Virus Download A"; fast_pattern; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; reference:md5,4c1e57a0388a703307319d17ae5e9039; classtype:trojan-activity; sid:2033747; rev:3; metadata:attack_target Client_Endpoint, created_at 2021_08_19, deployment Perimeter, malware_family Win32_Malgent_MSR, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_30;)