alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE W2KM_BARTALEX August 11 2015"; flow:to_server,established; http.uri; content:".jpg"; nocase; pcre:"/\/(?:[a-z]+|\d+)\.jpg/i"; http.user_agent; content:"Mozilla/4.0 (compatible|3b 20|MSIE 6.0|3b 20|Windows NT 5.1|3b 20|FSL 7.0.6.01001)"; fast_pattern; http.header_names; content:!"Accept"; content:!"Referer|0d 0a|"; reference:md5,1bcea0364088c5308ed217649eeef4d9; classtype:trojan-activity; sid:2021625; rev:5; metadata:created_at 2015_08_14, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_05_29;)