Rule History

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/GandCrab Ransomware CnC Activity M2"; flow:established,to_server; http.method; content:"POST"; http.uri; pcre:"/^\/[a-z]{3,20}(?:\?[a-z]{3,20}=[a-z]{0,10}&[a-z]{3,20}=[a-z]{0,10})?$/"; http.user_agent; content:"Mozilla/5.0 (Windows NT 6.1|3b 20|WOW64"; http.host; pcre:"/\.(?:bit|coin|sex|com|gandcrab\d*)$/"; http.request_body; pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/si"; http.content_len; byte_test:0,>,4000,0,string,dec; http.header_names; content:"|0d 0a|Host|0d 0a|Content-Type|0d 0a|User-Agent|0d 0a|Content-Length|0d 0a|Cache-Control|0d 0a 0d 0a|"; depth:67; fast_pattern; content:!"Accept"; content:!"Referer"; reference:md5,8b7d3093c477b2e99effde5065affbd5; classtype:command-and-control; sid:2025455; rev:7; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2018_03_06, deployment Perimeter, malware_family Win32_GandCrab, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_11_16, reviewed_at 2024_02_13, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;)