alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Java/Jacksbot Check-in"; flow:established,to_server; content:"|00 2d 00 68 00 20 00 32 00 66 00|"; pcre:"/^(?:4\x00[1-9a-f]|5\x00[\da])/Rs"; content:"|00 33 00 61 00|"; within:5; reference:md5,6d93fc6132ae6938013cdd95354bff4e; classtype:trojan-activity; sid:2017983; rev:3; metadata:created_at 2014_01_17, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)