alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Suspected Stealth Soldier Backdoor Related Activity M2 (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; bsize:11; content:"/mkv/MV.txt"; fast_pattern; http.header_names; to_lowercase; content:"|0d 0a|ua-cpu|0d 0a|"; content:!"|0d 0a|referer|0d 0a|"; reference:md5,0db6239ad0755392c31a09e58773cd3b; reference:md5,a418886a31852be25064d3573f2bc87d; reference:md5,1ea8a827ad4c565b1c2ae43b0a020092; reference:url,research.checkpoint.com/2023/stealth-soldier-backdoor-used-in-targeted-espionage-attacks-in-north-africa/; classtype:trojan-activity; sid:2046201; rev:3; metadata:attack_target Client_Endpoint, created_at 2023_06_12, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_30; target:src_ip;)