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PowerShell_JAB_B64

YARA detection rule by Florian Roth (Nextron Systems) · Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE

Detects base464 encoded $ sign at the beginning of a string

rule PowerShell_JAB_B64 {
   meta:
      description = "Detects base464 encoded $ sign at the beginning of a string"
      license = "Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE"
      author = "Florian Roth (Nextron Systems)"
      reference = "https://twitter.com/ItsReallyNick/status/980915287922040832"
      date = "2018-04-02"
      score = 60
      id = "c18fa17b-aaa5-5a89-bc25-3cc51b5af103"
   strings:
      $s1 = "('JAB" ascii wide
      $s2 = "powershell" nocase
   condition:
      filesize < 30KB and all of them
}

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

ea843d2a-e8c1-4bf8-a0e7-a3e54885836c

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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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