alert http1 $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Drokbk Checkin Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/index.php?passed="; fast_pattern; startswith; pcre:"/(?:AM|PM)$/"; http.header_names; content:!"Referer"; content:"|0d 0a|Host|0d 0a|Connection|0d 0a|"; startswith; reference:url,www.secureworks.com/blog/drokbk-malware-uses-github-as-dead-drop-resolver; classtype:trojan-activity; sid:2043014; rev:2; metadata:attack_target Client_Endpoint, created_at 2022_12_27, deployment Perimeter, deployment SSLDecrypt, malware_family Win32_Drokbk, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_03;)