MAL_Go_Modbus_Jul24_1

YARA detection rule by Florian Roth · NOASSERTION

Detects characteristics reported by Dragos for FrostyGoop ICS malware

rule MAL_Go_Modbus_Jul24_1 {
   meta:
      description = "Detects characteristics reported by Dragos for FrostyGoop ICS malware"
      author = "Florian Roth"
      reference = "https://hub.dragos.com/hubfs/Reports/Dragos-FrostyGoop-ICS-Malware-Intel-Brief-0724_.pdf"
      date = "2024-07-23"
      modified = "2024-07-24"
      score = 75
      hash1 = "5d2e4fd08f81e3b2eb2f3eaae16eb32ae02e760afc36fa17f4649322f6da53fb"
      id = "4a1e6bbe-d743-5394-b207-e417b64fa76d"
   strings:
      $a1 = "Go build"

      $sa1 = "github.com/rolfl/modbus"

      $sb1 = "main.TaskList.executeCommand"
      $sb2 = "main.TargetList.getTargetIpList"
      $sb3 = "main.TaskList.getTaskIpList"
      $sb4 = "main.CycleInfo" fullword
   condition:
      filesize < 30MB
      and (
         $sa1
         and 3 of ($sb*)
      )
      or 4 of them
}

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

482d5496-68dd-4ee0-8fa2-8d398e1922fe

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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

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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.

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