alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Campo Loader Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/campo/"; startswith; fast_pattern; pcre:"/^[a-z](?:[0-9])?\/[a-z](?:[0-9]?)$/R"; http.host; pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/"; http.header_names; content:!"Referer"; reference:url,orangecyberdefense.com/global/blog/cybersoc/in-the-eye-of-our-cybersoc-campo-loader-analysis-and-detection-perspectives/; reference:md5,c865db24e6a0ca317424eb1c1543426e; reference:md5,dd6c4275c1b7b761b6f96a7e1e2f3607; classtype:trojan-activity; sid:2032352; rev:2; metadata:attack_target Client_Endpoint, created_at 2021_03_30, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_08_10;)