EXPL_Log4j_CallBackDomain_IOCs_Dec21_1

YARA detection rule by Florian Roth · NOASSERTION

Detects IOCs found in Log4Shell incidents that indicate exploitation attempts of CVE-2021-44228

rule EXPL_Log4j_CallBackDomain_IOCs_Dec21_1 {
   meta:
      description = "Detects IOCs found in Log4Shell incidents that indicate exploitation attempts of CVE-2021-44228"
      author = "Florian Roth"
      reference = "https://gist.github.com/superducktoes/9b742f7b44c71b4a0d19790228ce85d8"
      date = "2021-12-12"
      score = 60
   strings:
      $xr1  = /\b(ldap|rmi):\/\/([a-z0-9\.]{1,16}\.bingsearchlib\.com|[a-z0-9\.]{1,40}\.interact\.sh|[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}):[0-9]{2,5}\/([aZ]|ua|Exploit|callback|[0-9]{10}|http443useragent|http80useragent)\b/
   condition:
      1 of them
}

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

458f22d9-5b1f-4abd-8773-7f8c2497ee75

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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 ]]

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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.

[[ 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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