Detection rules › Splunk
Windows Scheduled Task DLL Module Loaded
The following analytic detects instances where the taskschd.dll is loaded by processes running in suspicious or writable directories. This activity is unusual, as legitimate processes that load taskschd.dll typically reside in protected system locations. Malware or threat actors may attempt to load this DLL from writable or non-standard directories to manipulate the Task Scheduler and execute malicious tasks. By identifying processes that load taskschd.dll in these unsafe locations, this detection helps security analysts flag potentially malicious activity and investigate further to prevent unauthorized system modifications.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1053 Scheduled Task/Job |
| Persistence | T1053 Scheduled Task/Job |
| Privilege Escalation | T1053 Scheduled Task/Job |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 7 | Image loaded |
Stages and Predicates
Stage 1: search
search EventCode=7 Image IN ("*Recycle.bin*", "*\\PerfLogs\\*", "*\\Users\\Administrator\\Music\\*", "*\\Users\\Default\\*", "*\\Windows\\Media\\*", "*\\Windows\\servicing\\*", "*\\temp\\*", "*\\users\\public\\*", "*\\windows\\debug\\*", "*\\windows\\fonts\\*", "*\\windows\\temp\\*", "\\Windows\\repair\\*") ImageLoaded="*\\taskschd.dll"
Stage 2: fillnull
fillnull
Stage 3: stats
stats BY Image, ImageLoaded, dest, loaded_file, loaded_file_path, original_file_name, process_exec, process_guid, process_hash, process_id, process_name, process_path, service_dll_signature_exists, service_dll_signature_verified, signature, signature_id, user_id, vendor_product
Stage 4: search
search
Stage 5: search
search
Stage 6: 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 | in |
|
ImageLoaded | eq |
|
Neighbors
Broader alternatives (more inclusive than this rule)
These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.
- Windows Remote Access Software BRC4 Loaded Dll (drops 2 filters this rule applies)