Elastic high stable eql

Suspicious File Renamed via SMB

Identifies suspicious file rename operation by the virtual System process. This may indicate a remote ransomware attack via the SMB protocol.

View Source

Detection Logic

sequence by host.id, file.extension with maxspan=1s
 [file where host.os.type == "windows" and
  event.action == "rename" and process.pid == 4 and user.id : ("S-1-5-21*", "S-1-12-*") and
  file.extension != null and file.Ext.entropy >= 6 and file.path : "C:\\Users\\*" and
  file.Ext.original.name : ("*.jpg", "*.bmp", "*.png", "*.pdf", "*.doc", "*.docx", "*.xls", "*.xlsx", "*.ppt", "*.pptx", "*.lnk") and
  not file.extension : ("jpg", "bmp", "png", "pdf", "doc", "docx", "xls", "xlsx", "ppt", "pptx", "lnk")] with runs=3

Field Validations

Loading…

Comments (0)

Loading comments...