alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET ATTACK_RESPONSE VBA/Subdoc.B Obfuscated Payload Inbound"; flow:established,to_client; http.stat_code; content:"200"; http.content_type; content:"text/plain"; http.response_body; content:"|25 7b 20 5b|System|2e|Text|2e|Encoding|5d 3a 3a|UTF8|2e|GetString|28 5b|System|2e|Convert|5d 3a 3a|ToInt32|28 24 5f 2c|2|29 29 20 7d|"; fast_pattern; content:"|3b 28 5b|system|2e|String|5d 3a 3a|Join|28 27 27 2c 20 24|"; distance:0; pcre:"/\x24[0-9A-Za-z]{1,5}\x3d\x28\x27?(?:[0-9]{8}\x2c){4,}/"; reference:url,asec.ahnlab.com/en/32149/; reference:md5,9a6d8883adc662b4f53cd0b9cd1b28c3; classtype:trojan-activity; sid:2039080; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_10_03, deployment Perimeter, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_04_03, reviewed_at 2024_01_26, mitre_tactic_id TA0005, mitre_tactic_name Defense_Evasion, mitre_technique_id T1027, mitre_technique_name Obfuscated_Files_or_Information;)