Rule History

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Arkei/Vidar/Mars Stealer Variant Data Exfiltration Attempt"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/winsock"; fast_pattern; bsize:8; http.header_names; content:!"Referer"; http.request_body; content:"Content-Disposition|3a 20|form-data|3b 20|name|3d 22|file|22 3b 20|filename|3d 22|fname|22|"; content:"PK|03 04|"; distance:0; byte_test:1,<=,20,0,relative; content:"ProcList.txt"; distance:0; content:"Content-Disposition|3a 20|form-data|3b 20|name|3d 22|hwid|22 0d 0a 0d 0a|"; pcre:"/\{[0-9a-f]{8}-(?:[0-9a-f]{4}-){3}[0-9a-f]{12}\}/R"; reference:md5,844ab1b8a2db0242a20a6f3bbceedf6b; classtype:trojan-activity; sid:2038525; rev:1; metadata:created_at 2022_08_15, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_08_15, reviewed_at 2025_07_14;)