ET MALWARE BackConnect CnC Activity (Start VNC) M4

Query · suricata

flow:established,to_client;
flowbits:isset,ET.BackConnect;
content:"|1f 8b 08 08 11|"; startswith;
dsize:13;
threshold:type limit,track by_src,count 1,seconds 300;

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 BackConnect CnC Activity (Start VNC) M4 · 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-pkt $EXTERNAL_NET any -> $HOME_NET any (
    msg:"ET MALWARE BackConnect CnC Activity (Start VNC) M4";
    flow:established,to_client;
    flowbits:isset,ET.BackConnect;
    content:"|1f 8b 08 08 11|"; startswith;
    dsize:13;
    threshold:type limit,track by_src,count 1,seconds 300;
    reference:url,netresec.com/?page=Blog&month=2022-10&post=IcedID-BackConnect-Protocol;
    reference:url,twitter.com/netresec/status/1577966512459087874;
    reference:url,twitter.com/Unit42_Intel/status/1577773890012594177;
    classtype:command-and-control;
    sid:2050089; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2024_01_16, deployment Perimeter, malware_family BackConnect, confidence High, signature_severity Critical, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_01_16;
)

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