Windows Rundll32 WebDav With Network Connection
The following analytic detects the execution of rundll32.exe with command-line arguments loading davclnt.dll and the davsetcookie function to access a remote WebDav instance. It uses data from Endpoint Detection and…
Description
The following analytic detects the execution of rundll32.exe with command-line arguments loading davclnt.dll and the davsetcookie function to access a remote WebDav instance. It uses data from Endpoint Detection and Response (EDR) agents, correlating process execution and network traffic data. This activity is significant as it may indicate exploitation of CVE-2023-23397, a known vulnerability. If confirmed malicious, this could allow an attacker to establish unauthorized remote connections, potentially leading to data exfiltration or further network compromise.
Detection logic
Detection requirements
- Platform
- ESXiLinuxmacOSNetwork DevicesWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- sysmon_eventid_1_and_sysmon_eventid_3
Known benign triggers
- False positives will be present based on legitimate software, filtering may need to occur.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| msrc.microsoft.com/blog/2023/03/microsoft-mitigates-outlook-elevation-of-privilege-vulnerability/ | 2 |
| strontic.github.io/xcyclopedia/library/davclnt.dll-0EA3050E7CC710526E330C413C165DA0.html | 2 |
| twitter.com/ACEResponder/status/1636116096506818562?s=20 | 2 |
| twitter.com/domchell/status/1635999068282408962?s=20 | 2 |
| www.pwndefend.com/2023/03/15/the-long-game-persistent-hash-theft/ | 3from 2 sources |
From the source
- At source
- Open at source
- Upstream identifier
- f03355e0-28b5-4e9b-815a-6adffc63b38c
- Tagged by the source as
- CVE-2023-23397 Outlook Elevation of PrivilegeEndpointendpointSplunk CloudSplunk EnterpriseSplunk Enterprise Securityendpoint
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Aug 26, 2026
- Version
- 1