Malicious Webshell Written to Citrix NetScaler VPN Theme Directory (via file_event)
- Product
- linux
- Category
- file_event
- Author
- HuntRule
- Published
- 2026-07-23
- 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 the post-exploitation stage of Citrix NetScaler CVE-2026-8452 where a php webshell is dropped into the vpn theme directory after a pre-auth heap overflow. A php file in this template directory indicates appliance compromise.
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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