apt_nobelium_b64_to_Uint8Array

YARA detection rule by HydraDragonAntivirus · GPL-2.0

Detect Base64 decode to Uint8Array used in NOBELIUM HTML files

rule apt_nobelium_b64_to_Uint8Array {
  meta:
    id                = "66c9b00b-f021-4115-b9ec-d1e1f491ce72"
    description       = "Detect Base64 decode to Uint8Array used in NOBELIUM HTML files"
    hash              = "3d18bc4bfe1ec7b6b73a3fb39d490b64"
    version           = "1.0"
    creation_date     = "2021-12-02"
    modification_date = "2021-12-02"
    classification    = "TLP:WHITE"
    source            = "SEKOIA"

  strings:
    $a1 = "atob("
    $l0 = { 20 3c 20 [2-10] 2e 6c 65 6e 67 74 68 3b 20 69 2b 2b 29 7b }
    $l1 = { 5b 69 5d 20 3d 20 [2-10] 2e 63 68 61 72 43 6f 64 65 41 74 28 69 29 3b }
    $a2 = "new Uint8Array"

  condition:
    $l0 in (@a1..@a2) and
    $l1 in (@a1..@a2) and
    filesize > 1MB and filesize < 3MB
}

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

cff44ad3-1514-4bd4-b2cd-6238e52811b5

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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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