alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE QuickResponseC2 Default Tasking Struct"; flow:established,to_server; xbits:set,ET.QuickResponseC2.Checkin,track ip_pair,expire 60; http.method; content:"GET"; http.uri; content:"/command"; startswith; fast_pattern; pcre:"/^\d+/R"; content:".png"; endswith; http.header; content:"Accept-Encoding|3a 20|gzip|2c 20|deflate|0d 0a|Accept|3a 20 2a 2f 2a 0d 0a|Connection|3a 20|keep-alive|0d 0a|"; reference:url,github.com/kimd155/QuickResponseC2; classtype:trojan-activity; sid:2058173; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Mac_OSX, affected_product Linux, affected_product Windows_11, attack_target Client_and_Server, tls_state plaintext, created_at 2024_12_10, deployment Perimeter, malware_family QuickResponseC2, performance_impact Low, confidence High, signature_severity Major, tag C2_Framework, updated_at 2024_12_10, mitre_tactic_id TA0037, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel; target:src_ip;)