Microsoft Office Application Loading Task Scheduler DLL

 1title: Microsoft Office Application Loading Task Scheduler DLL
 2id: 8d1e674c-5c03-4be1-949c-4b85a472dc16
 3status: experimental
 4description: |
 5    Detects a Microsoft Office application loading taskschd.dll, which exposes COM interfaces for managing Windows Scheduled Tasks.
 6    This load is an early precursor to scheduled task creation or modification and has been frequently observed in macro-enabled
 7    malicious documents attempting to establish persistence.    
 8references:
 9    - https://github.com/saksham-17/detection-lab/blob/cbc25dfe1e5eda0c4e5a7d66b6d3bbd27829e158/T1053.005-scheduled-task/tests/test5-task-scheduler-via-VBA/report.md
10author: Saksham Bhattarai, Swachchhanda Shrawan Poudel (Nextron Systems)
11date: 2026-11-04
12tags:
13    - attack.persistence
14    - attack.privilege-escalation
15    - attack.t1053.005
16    - attack.execution
17    - attack.t1204.002
18logsource:
19    category: image_load
20    product: windows
21detection:
22    selection_dll:
23        - ImageLoaded|endswith: '\taskschd.dll'
24        - OriginalFileName: 'taskschd.dll'
25    selection_exe:
26        Image|endswith:
27            - '\eqnedt32.exe'
28            - '\excel.exe'
29            - '\fltldr.exe'
30            - '\graph.exe'
31            - '\msaccess.exe'
32            - '\mspub.exe'
33            - '\onenote.exe'
34            - '\onenoteim.exe'
35            - '\onenotem.exe'
36            - '\outlook.exe'
37            - '\powerpnt.exe'
38            - '\visio.exe'
39            - '\winproj.exe'
40            - '\winword.exe'
41    condition: all of selection_*
42falsepositives:
43    - Legitimate add-ins or automation scripts that use Office applications to manage scheduled tasks (rare in most environments)
44level: medium
45regression_tests_path: regression_data/rules/windows/image_load/image_load_office_taskschd_dll_load/info.yml