alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Gatak.DR Payload Instructions"; flow:established,to_server; urilen:45; http.method; content:"GET"; http.uri; content:"/uploads/"; depth:9; fast_pattern; content:".png"; distance:32; within:4; pcre:"/\/[a-f0-9]{32}\.png$/"; http.user_agent; content:"Mozilla/4.0 (compatible|3b 20|MSIE 8.0|3b 20|Windows NT 5.1|3b 20|Trident/4.0)"; http.header_names; content:!"Accept"; content:!"Referer|0d 0a|"; reference:url,microsoft.com/security/portal/threat/encyclopedia/entry.aspx?Name=Trojan:Win32/Gatak.DR#tab=2; classtype:trojan-activity; sid:2021160; rev:4; metadata:created_at 2015_05_29, malware_family Win32_Gatak_DR, signature_severity Major, updated_at 2024_04_30;)