Office Macro File Creation From Suspicious Process

 1title: Office Macro File Creation From Suspicious Process
 2id: b1c50487-1967-4315-a026-6491686d860e
 3status: test
 4description: Detects the creation of a office macro file from a a suspicious process
 5references:
 6    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1566.001/T1566.001.md
 7    - https://learn.microsoft.com/en-us/deployoffice/compat/office-file-format-reference
 8author: frack113, Nasreddine Bencherchali (Nextron Systems)
 9date: 2022-01-23
10modified: 2023-02-22
11tags:
12    - attack.initial-access
13    - attack.t1566.001
14logsource:
15    category: file_event
16    product: windows
17    definition: 'Requirements: The "ParentImage" field is not available by default on EID 11 of Sysmon logs. To be able to use this rule to the full extent you need to enriche the log with additional ParentImage data'
18detection:
19    selection_cmd:
20        - Image|endswith:
21              - '\cscript.exe'
22              - '\mshta.exe'
23              - '\regsvr32.exe'
24              - '\rundll32.exe'
25              - '\wscript.exe'
26        # Note: ParentImage is a custom field and is not available by default on Sysmon EID 11
27        - ParentImage|endswith:
28              - '\cscript.exe'
29              - '\mshta.exe'
30              - '\regsvr32.exe'
31              - '\rundll32.exe'
32              - '\wscript.exe'
33    selection_ext:
34        TargetFilename|endswith:
35            - '.docm'
36            - '.dotm'
37            - '.xlsm'
38            - '.xltm'
39            - '.potm'
40            - '.pptm'
41    condition: all of selection_*
42falsepositives:
43    - Unknown
44level: high