IMPORTANT: No additional bug fixes or documentation updates will be released for this version.
Anomalous Process For a Linux Populationedit
Searches for rare processes running on multiple Linux hosts in an entire fleet or network. This reduces the detection of false positives since automated maintenance processes usually only run occasionally on a single machine but are common to all or many hosts in a fleet.
Rule type: machine_learning
Machine learning job: linux_anomalous_process_all_hosts_ecs
Machine learning anomaly threshold: 50
Severity: low
Risk score: 21
Runs every: 15 minutes
Searches indices from: now-45m (Date Math format, see also Additional look-back time)
Maximum signals per execution: 100
References:
Tags:
- Elastic
- Linux
- ML
Version: 1
Added (Elastic Stack release): 7.7.0
Potential false positivesedit
A newly installed program or one that runs rarely as part of a monthly or quarterly workflow could trigger this signal.
Investigation guideedit
Signals from this rule indicate the presence of a Linux process that is rare and unusual for all of the monitored Linux hosts for which Auditbeat data is available. Here are some possible avenues of investigation:
- Consider the user as identified by the username field. Is this program part of an expected workflow for the user who ran this program on this host?
- Examine the history of execution. If this process manifested only very recently, it might be part of a new software package. If it has a consistent schedule - for example if it runs monthly or quarterly - it might be part of a monthly or quarterly business process.
- Examine the process arguments, title and working directory. These may provide indications as to the source of the program or the nature of the tasks it is performing.