alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Possible Win32/Qbot/Quakbot Checkin via HTTP GET"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".png?uid="; fast_pattern; pcre:"/\/\d+\.png\?uid=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})+$/"; http.user_agent; content:!"Mozilla"; http.header_names; content:"|0d 0a|Connection|0d 0a|Accept|0d 0a|Accept-Language|0d 0a|User-Agent|0d 0a|Host|0d 0a 0d 0a|"; depth:59; endswith; classtype:command-and-control; sid:2030157; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_05_12, deployment Perimeter, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_05_12;)