Microsoft Exchange Worker Spawning Suspicious Processes
editMicrosoft Exchange Worker Spawning Suspicious Processes
editIdentifies suspicious processes being spawned by the Microsoft Exchange Server worker process (w3wp). This activity may indicate exploitation activity or access to an existing web shell backdoor.
Rule type: eql
Rule indices:
- logs-endpoint.events.process-*
- winlogbeat-*
- logs-windows.sysmon_operational-*
- endgame-*
- logs-m365_defender.event-*
- logs-sentinel_one_cloud_funnel.*
Severity: high
Risk score: 73
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Initial Access
- Tactic: Execution
- Data Source: Elastic Endgame
- Data Source: Elastic Defend
- Data Source: Sysmon
- Data Source: Microsoft Defender for Endpoint
- Data Source: SentinelOne
Version: 309
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule query
editprocess where host.os.type == "windows" and event.type == "start" and
process.parent.name : "w3wp.exe" and process.parent.args : "MSExchange*AppPool" and
(process.name : ("cmd.exe", "powershell.exe", "pwsh.exe", "powershell_ise.exe") or
?process.pe.original_file_name in ("cmd.exe", "powershell.exe", "pwsh.dll", "powershell_ise.exe"))
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Initial Access
- ID: TA0001
- Reference URL: https://attack.mitre.org/tactics/TA0001/
-
Technique:
- Name: Exploit Public-Facing Application
- ID: T1190
- Reference URL: https://attack.mitre.org/techniques/T1190/
-
Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
-
Technique:
- Name: Command and Scripting Interpreter
- ID: T1059
- Reference URL: https://attack.mitre.org/techniques/T1059/
-
Sub-technique:
- Name: PowerShell
- ID: T1059.001
- Reference URL: https://attack.mitre.org/techniques/T1059/001/
-
Sub-technique:
- Name: Windows Command Shell
- ID: T1059.003
- Reference URL: https://attack.mitre.org/techniques/T1059/003/