alert tcp $HOME_NET any -> $EXTERNAL_NET 21 (msg:"ET MALWARE IrcBot Downloading Files via FTP"; flow:established,to_server; content:"RETR scrypt13"; depth:13; content:".cl"; distance:2; within:6; reference:md5,ca6208a4dd3f1f846aaaf4a6cbcc66ea; classtype:trojan-activity; sid:2022656; rev:1; metadata:created_at 2016_03_24, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)