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trojan_win_xe_backwash

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

The BACKWASH malware family, which acts as a reverse shell on the victim machine.

rule trojan_win_xe_backwash: XEGroup {
  meta:
    author          = "threatintel@volexity.com"
    date            = "2020-09-04"
    description     = "The BACKWASH malware family, which acts as a reverse shell on the victim machine."
    hash            = "815d262d38a26d5695606d03d5a1a49b9c00915ead1d8a2c04eb47846100e93f"
    memory_suitable = 1
    license         = "See license at https://github.com/volexity/threat-intel/blob/main/LICENSE.txt"

  strings:
    $pdb1 = "x:\\MultiOS_ReverseShell-master\\Multi-OS_ReverseShell\\obj\\Release\\XEReverseShell.pdb"
    $pdb2 = "\\Release\\XEReverseShell.pdb"

    $a1 = "RunServer" ascii
    $a2 = "writeShell" ascii
    $a3 = "GetIP" ascii

    $b1 = "xequit" wide
    $b2 = "setshell" wide

  condition:
    any of ($pdb*) or
    (
      (
        all of ($a*) or
        all of ($b*)
      ) and
      filesize < 40KB
    )
}

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

d778bd56-212d-41e7-8876-6e2d0d8d8ae8

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

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