Nautilus_rc4_key

YARA detection rule by NCSC UK · NOASSERTION

Rule for detection of Nautilus based on a hardcoded RC4 key

rule Nautilus_rc4_key {
    meta:
        description = "Rule for detection of Nautilus based on a hardcoded RC4 key"
        author = "NCSC UK"
        hash = "a415ab193f6cd832a0de4fcc48d5f53d6f0b06d5e13b3c359878c6c31f3e7ec3"
        date = "2017/11/23"
        reference = "https://www.ncsc.gov.uk/alerts/turla-group-malware"
        id = "124c8b95-46fb-5cc1-9b10-b10536e1781d"
    strings:
        $key = {31 42 31 34 34 30 44 39 30 46 43 39 42 43 42 34 36 41 39 41 43 39 36 34 33 38 46 45 45 41 38 42}
    condition:
        (uint16(0) == 0x5A4D and uint16(uint32(0x3c)) == 0x4550) and $key
}

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

c02f6af5-3832-409e-98e8-dcef50b31886

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

[[ reason ]]

What does this mean?

Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

[[ reason ]]

What do these messages mean?

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

[[ currentRule.title ]]

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