alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE BKDR_SLOTH.A Checkin"; flow:established,to_server; urilen:10; http.method; content:"GET"; http.uri; content:"/help.html"; fast_pattern; http.user_agent; content:"Mozilla/5.0 (compatible|3b 20|MSIE 7.0|3b 20|Windows NT 6.0)"; http.header_names; content:!"Accept|0d 0a|"; content:!"Referer|0d 0a|"; reference:md5,185e930a19ad1a99c226d59ef563e28c; reference:url,blog.trendmicro.com/trendlabs-security-intelligence/the-siesta-campaign-a-new-targeted-attack-awakens/; reference:url,fireeye.com/blog/technical/targeted-attack/2014/03/a-detailed-examination-of-the-siesta-campaign.html; classtype:command-and-control; sid:2018285; rev:6; metadata:created_at 2014_03_17, signature_severity Major, updated_at 2020_09_23;)