ET MALWARE SillyRAT CnC Command Inbound (Screenshot)

Query · suricata

flow:established,to_client;
flowbits:isset,ET.SillyRAT;
dsize:<32;
content:"c2NyZWVuc2hvdD"; startswith; fast_pattern;
threshold:type limit,count 1,seconds 300,track by_dst;
target:dest_ip;

Rule dependencies

⚠ Higher-order rule. It fires on other rules' alerts, not on raw events, so it cannot fire on its own. Deploy the rules it depends on too.

Depends on

Raw source ET MALWARE SillyRAT CnC Command Inbound (Screenshot) · Suricata
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Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged. 
alert tcp $EXTERNAL_NET any -> $HOME_NET any (
    msg:"ET MALWARE SillyRAT CnC Command Inbound (Screenshot)";
    flow:established,to_client;
    flowbits:isset,ET.SillyRAT;
    dsize:<32;
    content:"c2NyZWVuc2hvdD"; startswith; fast_pattern;
    threshold:type limit,count 1,seconds 300,track by_dst;
    reference:url,github.com/hash3liZer/SillyRAT;
    classtype:command-and-control;
    sid:2063517; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Linux, attack_target Client_Endpoint, tls_state plaintext, created_at 2025_07_16, deployment Perimeter, malware_family SillyRat, confidence High, signature_severity Critical, updated_at 2025_07_16, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1095, mitre_technique_name Non_Application_Layer_Protocol;
    target:dest_ip;
)

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