Techniques › T1505.003 › AN1109
AN1109 Analytic 1109
Linux · attack.mitre.org · ATT&CK Enterprise v19.2
<p>File creation of unauthorized script (e.g., .php, .sh) in /var/www/html followed by execution of unexpected system utilities (e.g., curl, bash, nc) by apache/nginx</p>
- Detects
- T1505.003 Web Shell
- Part of
- DET0394 Web Shell Detection via Server Behavior and File Execution Chains
Log sources and channels
Exactly as MITRE states them in x_mitre_log_source_references. Where a channel is vague, it is vague in the source; kevmap does not tidy it.
| Log source | Channel | Data component |
|---|---|---|
| auditd:SYSCALL | new file created in /var/www/html, /srv/http, or similar web root | DC0039 File Creation |
| auditd:SYSCALL | apache2 or nginx spawning sh, bash, or python interpreter | DC0032 Process Creation |
| NSM:Flow | POST requests to .php, .jsp, .aspx files with high entropy body | DC0085 Network Traffic Content |
Mutable elements
Parameters MITRE marks as environment-specific. These are the knobs you are expected to tune; they are why an analytic is not a rule.
| Field | Description |
|---|---|
WebRootPath | Web server root varies by distro and hosting configuration |
PayloadEntropyThreshold | Base64 or XOR encoded shells may exceed this value |
TimeWindow | Correlate file creation with process spawn within X seconds |
KEV CVEs whose mapped technique this analytic detects
| CVE | Vendor / product | State |
|---|---|---|
| CVE-2019-0604 | Microsoft SharePoint | Mapped |
| CVE-2019-18935 | Progress Telerik UI for ASP.NET AJAX | Mapped |
| CVE-2020-0688 | Microsoft Exchange Server | Mapped |
| CVE-2021-26855 | Microsoft Exchange Server | Mapped |
| CVE-2021-26857 | Microsoft Exchange Server | Mapped |
| CVE-2021-26858 | Microsoft Exchange Server | Mapped |
| CVE-2021-27065 | Microsoft Exchange Server | Mapped |
| CVE-2021-27860 | FatPipe WARP, IPVPN, and MPVPN software | Mapped |
| CVE-2021-40539 | Zoho ManageEngine | Mapped |
| CVE-2021-44077 | Zoho ManageEngine ServiceDesk Plus (SDP) / SupportCenter Plus | Mapped |
| CVE-2021-44228 | Apache Log4j2 | Mapped |
| CVE-2022-22954 | VMware Workspace ONE Access and Identity Manager | Mapped |
| CVE-2022-22963 | VMware Tanzu Spring Cloud | Mapped |
| CVE-2022-41082 | Microsoft Exchange Server | Mapped |
| CVE-2023-20118 | Cisco Small Business RV Series Routers | Mapped |
| CVE-2023-22952 | SugarCRM Multiple Products | Stale |
| CVE-2023-26360 | Adobe ColdFusion | Mapped |
| CVE-2023-32315 | Ignite Realtime Openfire | Mapped |
| CVE-2023-46805 | Ivanti Connect Secure and Policy Secure | Mapped |
| CVE-2024-21887 | Ivanti Connect Secure and Policy Secure | Mapped |
| CVE-2024-21893 | Ivanti Connect Secure, Policy Secure, and Neurons | Mapped |
| CVE-2025-31324 | SAP NetWeaver | Mapped |
| CVE-2025-35939 | Craft CMS Craft CMS | Mapped |
| CVE-2025-3928 | Commvault Web Server | Mapped |
| CVE-2025-42999 | SAP NetWeaver | Mapped |
| CVE-2025-4427 | Ivanti Endpoint Manager Mobile (EPMM) | Mapped |