ET MALWARE SYNful Knock Cisco IOS Router Implant CnC Beacon (INBOUND)

Query · suricata

flow:established,to_server;
content:"|00 00 00 00|text|00|";
byte_jump:4,0,relative,post_offset -1;
isdataat:!2,relative;
Raw source ET MALWARE SYNful Knock Cisco IOS Router Implant CnC Beacon (INBOUND) · Suricata
Esc
Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged. 
alert tcp any any -> $HOME_NET 80 (
    msg:"ET MALWARE SYNful Knock Cisco IOS Router Implant CnC Beacon (INBOUND)";
    flow:established,to_server;
    content:"|00 00 00 00|text|00|";
    byte_jump:4,0,relative,post_offset -1;
    isdataat:!2,relative;
    reference:url,fireeye.com/blog/threat-research/2015/09/synful_knock_-_acis.html;
    classtype:command-and-control;
    sid:2021785; rev:3;
    metadata:attack_target Client_Endpoint, created_at 2015_09_16, deployment Perimeter, signature_severity Major, tag c2, updated_at 2019_07_26, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)

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