capa_asp_obfuscation_obviously

YARA detection rule by Arnim Rupp · https://creativecommons.org/licenses/by-nc/4.0/

ASP obfuscation functions which are very obvious because they don't have a legitimate use (I can imageing ;)

rule capa_asp_obfuscation_obviously: WEBSHELL PROD {
  meta:
    description = "ASP obfuscation functions which are very obvious because they don't have a legitimate use (I can imageing ;)"
    license     = "https://creativecommons.org/licenses/by-nc/4.0/"
    author      = "Arnim Rupp"
    date        = "2021/03/14"
    score       = 60

  strings:
    $oo1 = /\w\"&\"\w/ wide ascii
    $oo2 = "*/\").Replace(\"/*" wide ascii

  condition:
    (
      filesize < 100KB and
      (
        (#oo1) > 2 or
        $oo2
      )
    ) or (
      filesize < 25KB and
      (
        (#oo1) > 1
      )
    ) or (
      filesize < 1KB and
      (
        (#oo1) > 0
      )
    )
}

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

8de51505-f770-42a0-a9f4-55b1e1e807e6

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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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