alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE [ANY.RUN] DarkCrystal Rat Check-in (POST)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php"; endswith; http.content_len; byte_test:0,>,320,0,string,dec; byte_test:0,<,370,0,string,dec; http.request_body; content:"|05 06 02 01 02|"; offset:8; depth:5; fast_pattern; http.header; content:"Expect|3a 20|100|2d|continue|0d 0a|Connection|3a 20|"; http.header_names; content:"|0d 0a|Content-Type|0d 0a|User-Agent|0d 0a|Host|0d 0a|Content-Length|0d 0a|Expect|0d 0a|Connection|0d 0a 0d 0a|"; bsize:72; reference:md5,8dd1baebdcaee56ce4e4382e7071bd3d; reference:url,app.any.run/tasks/730814fe-b061-4b67-8ff1-4455998e99f6; classtype:trojan-activity; sid:2048095; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_09_15, deployment Perimeter, malware_family DCRat, confidence High, signature_severity Critical, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_09_20, reviewed_at 2024_01_26;)