Rule History

alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE [ANY.RUN] Win32/ObserverStealer CnC Response"; flow:established,to_client; http.response_body; content:"gecko|3b|chromium|3b|download|3b|grabbers|3b|extensions|3b|processGrabber|3b|dll|3b|"; startswith; fast_pattern; content:"|0d 0d 0a 0a 0a|Firefox|0a 25|USERPROFILE|25|"; distance:0; reference:url,twitter.com/Jane_0sint/status/1666019485583659008; reference:md5,c28cc92a7c78b96bec58fa3e5398074a; reference:url,community.emergingthreats.net/t/observerstealer/624; reference:url,app.any.run/tasks/5728c30e-00c1-4f87-9522-ff8b9e08fa32/; classtype:trojan-activity; sid:2046155; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_06_07, deployment Perimeter, malware_family ObserverStealer, confidence High, signature_severity Critical, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_06_07;)