Searches for rare processes running on multiple 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: windows_anomalous_process_all_hosts_ecs
Machine learning anomaly threshold: 50
Risk score: 21
Runs every: 15 minutes
Maximum alerts per execution: 100
- Threat Detection
Version: 3 (version history)
Added (Elastic Stack release): 7.7.0
Last modified (Elastic Stack release): 7.10.0
Rule authors: Elastic
Rule license: Elastic License
A newly installed program or one that runs rarely as part of a monthly or quarterly workflow could trigger this alert.
Alerts from this rule indicate the presence of a Windows process that is rare and unusual for all of the Windows hosts for which Winlogbeat 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 metadata like the values of the Company, Description and Product fields, which may indicate whether the program is associated with an expected software vendor or package.
- Examine arguments and working directory. These may provide indications as to the source of the program or the nature of the tasks it is performing.
- Consider the same for the parent process. If the parent process is a legitimate system utility or service, this could be related to software updates or system management. If the parent process is something user-facing like an Office application, this process could be more suspicious.
- If you have file hash values in the event data, and you suspect malware, you can optionally run a search for the file hash to see if the file is identified as malware by anti-malware tools.
- Version 3 (7.10.0 release)
- Formatting only
- Version 2 (7.9.0 release)
- Formatting only