alert smtp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/DarkCloud Exfil Over SMTP (Subject)"; flow:established,to_server; content:"Subject|3a 20|DarkCloud|20|Credentials|3a 3a 3a|"; fast_pattern; reference:url,twitter.com/James_inthe_box/status/1572676263462174721; reference:md5,a498f17c44a6762c239d21cc12afec19; classtype:trojan-activity; sid:2043218; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_01_05, deployment Perimeter, malware_family Win32_DarkCloud, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_01_05;)