alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE PE EXE or DLL Windows file download Text M2"; flow:established,from_server; file_data; content:"4D5A"; nocase; within:4; content:"50450000"; distance:0; content:"21546869732070726f6772616d"; nocase; fast_pattern; classtype:trojan-activity; sid:2022640; rev:2; metadata:created_at 2016_03_23, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)