sequence by host.id with maxspan=1s
[network where host.os.type == "windows" and
event.action == "connection_accepted" and destination.port == 445 and source.port >= 49152 and process.pid == 4 and
source.ip != "127.0.0.1" and source.ip != "::1" and
network.type == "ipv4" and not endswith(source.address, destination.address)]
[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
Install detection rules in Elastic Security
Detect Suspicious File Renamed via SMB in the Elastic Security detection engine by installing this rule into your Elastic Stack.
To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).