alert http1 $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Cobalt Strike Malleable C2 OCSP Profile"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/oscp/"; fast_pattern; startswith; pcre:"/^\/oscp\/[a-z]+$/"; http.host; bsize:17; content:"ocsp.verisign.com"; http.user_agent; bsize:23; content:"Microsoft-CryptoAPI/6.1"; http.header_names; content:!"|0d 0a|Referer|0d 0a|"; content:"|0d 0a|Host|0d 0a|Accept|0d 0a|"; startswith; reference:md5,2ba2e7af1246da08e4fd7345c7207b59; reference:url,github.com/rsmudge/Malleable-C2-Profiles/blob/master/normal/oscp.profile; classtype:command-and-control; sid:2032750; rev:7; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_05_15, deployment Perimeter, malware_family Cobalt_Strike, confidence Medium, signature_severity Major, updated_at 2024_04_14, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)