ATT&CK coverage › Technique
System Binary Proxy Execution: Rundll32 T1218.011
Adversaries may abuse rundll32.exe to proxy execution of malicious code. Using rundll32.exe, vice executing directly (i.e. Shared Modules), may avoid triggering security tools that may not monitor execution of the rundll32.exe process because of allowlists or false positives from normal operations. Rundll32.exe is commonly associated with executing DLL payloads (ex: <code>rundll32.exe {DLLname, DLLfunction}</code>).
Events covered
10 catalog events are tagged with this technique by at least one rule.
Authoring guide
Patterns shared across the 35 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.
Fields filtered most (25 distinct)
The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.
Top indicator values (279 distinct)
Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique.
Common exclusions (8 distinct)
Field/operator/value combinations that rules under this technique routinely exclude (top-level not() clauses). These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths.
Rules under this technique
Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.
Sigma 27 rules
- Bad Opsec Defaults Sacrificial Processes With Improper Arguments
- CobaltStrike Load by Rundll32
- Code Execution via Pcwutl.dll
- HackTool - F-Secure C3 Load by Rundll32
- HackTool - RedMimicry Winnti Playbook Execution
- HTML Help HH.EXE Suspicious Child Process
- Outbound Network Connection To Public IP Via Winlogon
- Potential PowerShell Execution Via DLL
- Potentially Suspicious Rundll32 Activity
- Potentially Suspicious Rundll32.EXE Execution of UDL File
- Process Access via TrolleyExpress Exclusion
- Remote Thread Creation Via PowerShell In Uncommon Target
- Rundll32 Execution With Uncommon DLL Extension
- Rundll32 InstallScreenSaver Execution
- Rundll32 Internet Connection
- RunDLL32 Spawning Explorer
- Rundll32 UNC Path Execution
- SCR File Write Event
- ScreenSaver Registry Key Set
- Shell32 DLL Execution in Suspicious Directory
- Suspicious Control Panel DLL Load
- Suspicious HH.EXE Execution
- Suspicious Rundll32 Activity Invoking Sys File
- Suspicious Rundll32 Execution With Image Extension
- Suspicious Rundll32 Setupapi.dll Activity
- Suspicious ShellExec_RunDLL Call Via Ordinal
- Unsigned DLL Loaded by Windows Utility
Elastic 1 rule
Splunk 5 rules
- Rundll32 DNSQuery
- Rundll32 Process Creating Exe Dll Files
- Rundll32 with no Command Line Arguments with Network
- Windows LOLBAS Executed Outside Expected Path
- Windows Rundll32 Load DLL in Temp Dir