alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Shylock Module Server Response"; flow:established,from_server; content:"|0d 0a 0d 0a 23 23 23|ERROR_SRC|23 23 23|"; content:"|23 23 23|ERROR_SRC_END|23 23 23|"; distance:0; reference:md5,4fda5e7e8e682870e993f97ad26ba6b2; classtype:trojan-activity; sid:2013688; rev:2; metadata:created_at 2011_09_22, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)