Ross Wolf
5fcece8416
Co-Authored-By: Brent Murphy <56412096+bm11100@users.noreply.github.com> Co-Authored-By: Craig Chamberlain <randomuserid@users.noreply.github.com> Co-Authored-By: David French <56409778+threat-punter@users.noreply.github.com> Co-Authored-By: Derek Ditch <dcode@users.noreply.github.com> Co-Authored-By: Justin Ibarra <brokensound77@users.noreply.github.com>
41 lines
2.5 KiB
TOML
41 lines
2.5 KiB
TOML
[metadata]
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creation_date = "2020/03/25"
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ecs_version = ["1.5.0"]
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maturity = "production"
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updated_date = "2020/03/25"
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[rule]
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anomaly_threshold = 50
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author = ["Elastic"]
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description = """
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Searches for rare processes running on multiple hosts in an entire fleet or network. This reduces the detection of false
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positives since automated maintenance processes usually only run occasionally on a single machine but are common to all
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or many hosts in a fleet.
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"""
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false_positives = [
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"""
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A newly installed program or one that runs rarely as part of a monthly or quarterly workflow could trigger this
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signal.
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""",
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]
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from = "now-45m"
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interval = "15m"
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license = "Elastic License"
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machine_learning_job_id = "windows_anomalous_process_all_hosts_ecs"
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name = "Anomalous Process For a Windows Population"
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note = """### Investigating an Unusual Windows Process ###
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Signals 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:
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- 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?
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- 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 cadence - for example if it runs monthly or quarterly - it might be part of a monthly or quarterly business process.
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- 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.
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- 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.
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- 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.
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- 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. """
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references = ["https://www.elastic.co/guide/en/siem/guide/current/prebuilt-ml-jobs.html"]
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risk_score = 21
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rule_id = "6e40d56f-5c0e-4ac6-aece-bee96645b172"
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severity = "low"
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tags = ["Elastic", "ML", "Windows"]
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type = "machine_learning"
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