[[ fm.text ]] Click here

apt_win_freshfire

YARA detection rule by threatintel@volexity.com · See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt

The FRESHFIRE malware family. The malware acts as a downloader, pulling down an encrypted snippet of code from a remote source, executing it, and deleting it from the remote server.

import "pe"
rule apt_win_freshfire: APT29 {
  meta:
    author      = "threatintel@volexity.com"
    date        = "2021-05-27"
    description = "The FRESHFIRE malware family. The malware acts as a downloader, pulling down an encrypted snippet of code from a remote source, executing it, and deleting it from the remote server."
    hash        = "ad67aaa50fd60d02f1378b4155f69cffa9591eaeb80523489a2355512cc30e8c"
    license     = "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt"

  strings:
    $uniq1 = "UlswcXJJWhtHIHrVqWJJ"
    $uniq2 = "gyibvmt\x00"

    $path1 = "root/time/%d/%s.json"
    $path2 = "C:\\dell.sdr"
    $path3 = "root/data/%d/%s.json"

  condition:
    (
      pe.number_of_exports == 1 and
      pe.exports("WaitPrompt")
    ) or
    any of ($uniq*) or
    2 of ($path*)
}

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

7b3d3864-f9ad-4c0f-93f8-bac4982e6aff

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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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