alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE IIStealer Inbound Exfil Request M2"; flow:established,to_server; http.uri; content:"/checkout/Payment.aspx"; bsize:22; http.header; content:"|0d 0a|X-IIS-Data|3a 20|"; fast_pattern; reference:url,i.blackhat.com/USA21/Wednesday-Handouts/us-21-Anatomy-Of-Native-Iis-Malware-wp.pdf; classtype:trojan-activity; sid:2033707; rev:1; metadata:attack_target Server, created_at 2021_08_11, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_08_11;)