alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE DonotGroup Maldoc Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; pcre:"/^\/[A-Za-z0-9]{20}\/[A-Za-z0-9]{17,20}$/"; http.header_names; content:"|0d 0a|User-Agent|0d 0a|Host|0d 0a|Cache-Control|0d 0a 0d 0a|"; fast_pattern; bsize:37; classtype:trojan-activity; sid:2044734; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_03_21, deployment Perimeter, performance_impact Moderate, confidence Low, signature_severity Minor, tag Donot, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_05_19, reviewed_at 2023_10_23; target:src_ip;)