alert smtp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET ADWARE_PUP Win32/InstallDisck SMTP Checkin"; flow:established,to_server; content:"Subject: PCInfo:"; fast_pattern; content:"<li>User Name:<b>"; content:"PC Name:<b>"; distance:0; content:"<li>Proxy:<b>"; distance:0; content:"Gateway:<b>"; distance:0; reference:md5,b79640ae0cf9f3ad58b14c15c50f3de3; classtype:pup-activity; sid:2029186; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_12_20, deployment Perimeter, performance_impact Low, confidence High, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_12_20;)