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Suspicious Process Access via Direct System Call
editSuspicious Process Access via Direct System Call
editIdentifies suspicious process access events from unknown memory region. Endpoint security solutions usually hook userland Windows APIs in order to decide if the code that is being executed is malicious or not. It’s possible to bypass hooked functions by writing malicious functions that call syscalls directly.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-windows.*
Severity: high
Risk score: 73
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
- Defense Evasion
Version: 1
Added (Elastic Stack release): 7.16.0
Rule authors: Elastic
Rule license: Elastic License v2
Rule query
editprocess where event.code == "10" and length(winlog.event_data.CallTrace) > 0 and /* Sysmon CallTrace starting with unknown memory module instead of ntdll which host Windows NT Syscalls */ not winlog.event_data.CallTrace : ("?:\\WINDOWS\\SYSTEM32\\ntdll.dll*", "?:\\WINDOWS\\SysWOW64\\ntdll.dll*")
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Process Injection
- ID: T1055
- Reference URL: https://attack.mitre.org/techniques/T1055/