alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Upload to Links-Server File Sharing Server"; flow:established,to_server; urilen:7; http.method; content:"POST"; http.uri; content:"/upload"; http.request_body; content:"|0d 0a|Content|2d|Disposition|3a 20|form|2d|data|3b 20|name|3d 22|expires|22 0d 0a 0d 0a|"; pcre:"/^(?:[0-9]{7})/R"; content:"|0d 0a 2d 2d 2d 2d 2d 2d 2d 2d|"; within:10; content:"|0d 0a|Content|2d|Disposition|3a 20|form|2d|data|3b 20|name|3d 22|access_key|22 0d 0a 0d 0a 0d 0a 2d 2d 2d 2d 2d|"; fast_pattern; content:"|0d 0a|Content|2d|Disposition|3a 20|form|2d|data|3b 20|name|3d 22|expires|22 0d 0a 0d 0a|"; distance:0; pcre:"/^(?:[0-9]{7})/R"; reference:url,github.com/xtrafrancyz/linx-server; classtype:misc-activity; sid:2046809; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_07_12, deployment Perimeter, deployment SSLDecrypt, performance_impact Moderate, confidence Low, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_07_12;)