alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Linux/dtool IRC Command (STOP)"; flow:established,from_server; content:"PRIVMSG"; content:"{STOP} Stop command ->"; fast_pattern; nocase; reference:url,kernelmode.info/forum/viewtopic.php?f=16&t=4048&p=26845#p26845; reference:md5,a60b96a2cf4b979968fe5ac6259fb197; classtype:trojan-activity; sid:2021879; rev:4; metadata:created_at 2015_10_01, signature_severity Major, updated_at 2019_10_08;)