alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Maldoc Sending Registration Information (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/target?id="; startswith; fast_pattern; http.user_agent; content:"|3b 20|.NET CLR 3.0.30729|3b 20|.NET CLR 3.5.30729|3b 20|"; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; reference:url,nsfocusglobal.com/warning-newly-discovered-apt-attacker-atlascross-exploits-red-cross-blood-drive-phishing-for-cyberattack/; reference:md5,7195d7e4926a0a85fbe81e40ab7c0ca4; reference:md5,459ebb0896943a34252c758185105ef9; classtype:trojan-activity; sid:2048319; rev:2; metadata:attack_target Client_Endpoint, created_at 2023_09_28, deployment Perimeter, malware_family AtlasCross, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_27, reviewed_at 2023_09_28; target:src_ip;)