IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
Microsoft Exchange Server UM Spawning Suspicious Processesedit
Identifies suspicious processes being spawned by the Microsoft Exchange Server Unified Messaging (UM) service. This activity has been observed exploiting CVE-2021-26857.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
- winlogbeat-*
- logs-windows.*
- endgame-*
Severity: medium
Risk score: 47
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
- Data Source: Elastic Endgame
- Use Case: Vulnerability
Version: 103
Rule authors:
- Elastic
- Austin Songer
Rule license: Elastic License v2
Investigation guideedit
Rule queryedit
process where host.os.type == "windows" and event.type == "start" and
process.parent.name : ("UMService.exe", "UMWorkerProcess.exe") and
not process.executable :
("?:\\Windows\\System32\\werfault.exe",
"?:\\Windows\\System32\\wermgr.exe",
"?:\\Program Files\\Microsoft\\Exchange Server\\V??\\Bin\\UMWorkerProcess.exe",
"D:\\Exchange 2016\\Bin\\UMWorkerProcess.exe",
"E:\\ExchangeServer\\Bin\\UMWorkerProcess.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/