Unusual Print Spooler Child Processedit
Detects unusual Print Spooler service (spoolsv.exe) child processes. This may indicate an attempt to exploit privilege escalation vulnerabilities related to the Printing Service on Windows.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
- logs-windows.*
Severity: medium
Risk score: 47
Runs every: 5 minutes
Searches indices from: now-9m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Privilege Escalation
Version: 6 (version history)
Added (Elastic Stack release): 7.14.0
Last modified (Elastic Stack release): 8.3.0
Rule authors: Elastic
Rule license: Elastic License v2
Potential false positivesedit
Install or update of a legitimate printing driver. Verify the printer driver file metadata such as manufacturer and signature information.
Investigation guideedit
## Config If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.
Rule queryedit
process where event.type == "start" and process.parent.name : "spoolsv.exe" and (?process.Ext.token.integrity_level_name : "System" or ?winlog.event_data.IntegrityLevel : "System") and /* exclusions for FP control below */ not process.name : ("splwow64.exe", "PDFCreator.exe", "acrodist.exe", "spoolsv.exe", "msiexec.exe", "route.exe", "WerFault.exe") and not process.command_line : "*\\WINDOWS\\system32\\spool\\DRIVERS*" and not (process.name : "net.exe" and process.command_line : ("*stop*", "*start*")) and not (process.name : ("cmd.exe", "powershell.exe") and process.command_line : ("*.spl*", "*\\program files*", "*route add*")) and not (process.name : "netsh.exe" and process.command_line : ("*add portopening*", "*rule name*")) and not (process.name : "regsvr32.exe" and process.command_line : "*PrintConfig.dll*")
Threat mappingedit
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Privilege Escalation
- ID: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
-
Technique:
- Name: Exploitation for Privilege Escalation
- ID: T1068
- Reference URL: https://attack.mitre.org/techniques/T1068/
Rule version historyedit
- Version 6 (8.3.0 release)
-
- Formatting only
- Version 5 (8.2.0 release)
-
-
Updated query, changed from:
process where event.type == "start" and process.parent.name : "spoolsv.exe" and (process.Ext.token.integrity_level_name : "System" or winlog.event_data.IntegrityLevel : "System") and /* exclusions for FP control below */ not process.name : ("splwow64.exe", "PDFCreator.exe", "acrodist.exe", "spoolsv.exe", "msiexec.exe", "route.exe", "WerFault.exe") and not process.command_line : "*\\WINDOWS\\system32\\spool\\DRIVERS*" and not (process.name : "net.exe" and process.command_line : ("*stop*", "*start*")) and not (process.name : ("cmd.exe", "powershell.exe") and process.command_line : ("*.spl*", "*\\program files*", "*route add*")) and not (process.name : "netsh.exe" and process.command_line : ("*add portopening*", "*rule name*")) and not (process.name : "regsvr32.exe" and process.command_line : "*PrintConfig.dll*")
-
- Version 3 (8.1.0 release)
-
-
Updated query, changed from:
process where event.type == "start" and process.parent.name : "spoolsv.exe" and user.id : "S-1-5-18" and /* exclusions for FP control below */ not process.name : ("splwow64.exe", "PDFCreator.exe", "acrodist.exe", "spoolsv.exe", "msiexec.exe", "route.exe", "WerFault.exe") and not process.command_line : "*\\WINDOWS\\system32\\spool\\DRIVERS*" and not (process.name : "net.exe" and process.command_line : ("*stop*", "*start*")) and not (process.name : ("cmd.exe", "powershell.exe") and process.command_line : ("*.spl*", "*\\program files*", "*route add*")) and not (process.name : "netsh.exe" and process.command_line : ("*add portopening*", "*rule name*")) and not (process.name : "regsvr32.exe" and process.command_line : "*PrintConfig.dll*")
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