Possible ransomware activities

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About the rule

Rule Type

Advanced

Rule Description

Multiple file modifications are detected soon after a new process creation, typical of ransomware attacks.

Severity

Critical

Rule Requirement

Criteria

Action1: actionname = "null" Action2: actionname = "File modified" AND USERNAME = Action1.USERNAME AND HOSTNAME = Action1.HOSTNAME AND PROCESSNAME = Action1.PROCESSNAME | timewindow 15m | groupby HOSTNAME | groupby USERNAME | groupby PROCESSNAME having COUNT > 15 sequence:Action1 followedby Action2 within 5m select Action2.timewindow.HOSTNAME,Action2.timewindow.MESSAGE,Action2.timewindow.USERNAME,Action2.timewindow.DOMAIN,Action2.timewindow.OBJECTNAME,Action2.timewindow.PROCESSNAME,Action2.timewindow.ACCESSLIST

Detection

Execution Mode

realtime

Log Sources

Windows