alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE SysJoker User-Agent Observed"; flow:established,to_server; http.user_agent; bsize:107; content:"Mozilla|2f|5|2e|0|20 28|Windows|20|NT|20|10|2e|0|3b 20|WOW64|29 20|AppleWebKit|2f|537|2e|36|20 28|KHTML|2c 20|like|20|Gecko|29 20|Chrome|2f|92|2e|0|2e|4515|2e|159|20|Safari|2f|537"; fast_pattern; threshold:type limit,seconds 300,count 1,track by_src; reference:url,research.checkpoint.com/2023/israel-hamas-war-spotlight-shaking-the-rust-off-sysjoker; reference:url,intezer.com/blog/research/wildcard-evolution-of-sysjoker-cyber-threat; classtype:trojan-activity; sid:2049303; rev:2; metadata:created_at 2023_11_27, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_03_27;)