alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE FireEye.STX RAT Checkin"; flow:established,to_server; content:"GET /WinData.DLL?HELO-STX-1*"; depth:28; content:"$|0D 0A|"; within:40; reference:url,blog.fireeye.com/research/2012/04/spear-phished-by-fireeye.html; reference:md5,89217de164ffca0f0fed54a8003eb98f; classtype:command-and-control; sid:2014632; rev:3; metadata:created_at 2012_04_23, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_20;)