EXPL_Office_TemplateInjection_Aug19_RID3419

YARA detection rule by Florian Roth · CC-BY-NC https://creativecommons.org/licenses/by-nc/4.0/

Detects possible template injections in Office documents, particularly those that load content from external sources

rule EXPL_Office_TemplateInjection_Aug19_RID3419 : DEMO EXPLOIT OFFICE T1203 T1221 T1566_001 {
   meta:
      description = "Detects possible template injections in Office documents, particularly those that load content from external sources"
      author = "Florian Roth"
      reference = "https://attack.mitre.org/techniques/T1221/"
      date = "2019-08-22 15:16:01"
      score = 75
      customer = "demo"
      license = "CC-BY-NC https://creativecommons.org/licenses/by-nc/4.0/"
      modified = "2025-03-20"
      tags = "DEMO, EXPLOIT, OFFICE, T1203, T1221, T1566_001"
      minimum_yara = "3.5.0"
      
   strings:
      $x1 = /attachedTemplate" Target="http[s]?:\/\/[^"]{4,60}/ ascii
      $fp1 = ".sharepoint.com" 
      $fp2 = ".office.com" 
   condition: 
      filesize < 20MB and $x1 and not 1 of ( $fp* )
}

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

f4f72552-66e7-45eb-9911-39d348c23cd0

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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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