具有异常扩展名的存档文件

编辑

识别创建具有异常扩展名的存档文件。攻击者可能会尝试使用图像、音频或文档文件类型使用的文件扩展名值伪装文件以逃避检测。

规则类型: eql

规则索引:

  • logs-endpoint.events.file-*

严重性: 低

风险评分: 21

每隔: 5 分钟

搜索索引自: now-9m (日期数学格式,另请参见 额外回溯时间)

每次执行的最大告警数: 100

参考: 无

标签:

  • 领域:端点
  • 操作系统:Windows
  • 用例:威胁检测
  • 策略:防御规避
  • 数据源:Elastic Defend
  • 规则类型:BBR

版本: 2

规则作者:

  • Elastic

规则许可证: Elastic License v2

规则查询

编辑
file where host.os.type == "windows" and event.action != "deletion" and

  /* common archive file headers - Rar, 7z, GZIP, MSCF, XZ, ZIP */
  file.Ext.header_bytes : ("52617221*", "377ABCAF271C*", "1F8B*", "4d534346*", "FD377A585A00*", "504B0304*", "504B0708*") and

  (
    /* common image file extensions */
    file.extension : ("jpg", "jpeg", "emf", "tiff", "gif", "png", "bmp", "ico", "fpx", "eps", "inf") or

    /* common audio and video file extensions */
    file.extension : ("mp3", "wav", "avi", "mpeg", "flv", "wma", "wmv", "mov", "mp4", "3gp") or

    /* common document file extensions */
    (file.extension : ("doc", "docx", "rtf", "ppt", "pptx", "xls", "xlsx") and

    /* exclude ZIP file header values for OPENXML documents */
    not file.Ext.header_bytes : ("504B0304*", "504B0708*"))
  ) and

  not (process.executable : "?:\\Windows\\System32\\inetsrv\\w3wp.exe" and file.path : "?:\\inetpub\\temp\\IIS Temporary Compressed Files\\*")

框架: MITRE ATT&CKTM