Detection rules › Splunk
Rundll32 Process Creating Exe Dll Files
The following analytic detects a rundll32 process creating executable (.exe) or dynamic link library (.dll) files. It leverages Sysmon EventCode 11 to identify instances where rundll32.exe generates these file types. This activity is significant because rundll32 is often exploited by malware, such as IcedID, to drop malicious payloads in directories like Temp, AppData, or ProgramData. If confirmed malicious, this behavior could allow an attacker to execute arbitrary code, establish persistence, or escalate privileges within the environment.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Defense Evasion | T1218.011 System Binary Proxy Execution: Rundll32 |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 11 | FileCreate |
Stages and Predicates
Stage 1: search
search EventCode=11 Image="*rundll32.exe" TargetFilename IN ("*.dll", "*.exe")
Stage 2: stats
stats BY action, dest, file_name, file_path, process_guid, process_id, user_id, vendor_product
Stage 3: search
search
Stage 4: search
search
Stage 5: search
search `macro`
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
Image | eq |
|
TargetFilename | in |
|