Malicious Phantom Taurus OutlookEN Web Shell File Creation (via file_event)
- Category
- file_event
- Author
- HuntRule
- Published
- 2026-07-20
- Updated
- 2026-08-28
ATT&CK techniques
PersistenceRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects creation of the OutlookEN.aspx web shell dropped by Phantom Taurus on compromised Exchange and IIS servers. The web shell loads the NET-STAR IIServerCore backdoor into the worker process to provide persistent server access. Detecting the file drop catches the initial foothold before the backdoor is loaded into memory.
Reporting behind it
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
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Also included
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