Rule History

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Operation Silk Lure Payload Request"; flow:established,to_server; urilen:46; http.method; content:"GET"; http.uri; content:"/down.php/"; startswith; pcre:"/^(?:[a-z0-9]{32})\x2e\w{3}$/R"; http.user_agent; content:"WindowsPowerShell"; fast_pattern; reference:md5,f5b9ad341ccfe06352b8818b90b2413e; reference:url,seqrite.com/blog/operation-silk-lure-scheduled-tasks-weaponized-for-dll-side-loading-drops-valleyrat; classtype:trojan-activity; sid:2065257; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2025_10_20, deployment Perimeter, deployment SSLDecrypt, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_10_20, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1105, mitre_technique_name Ingress_Tool_Transfer; target:src_ip;)