Suspicious Child Process of AspNetCompiler

 1title: Suspicious Child Process of AspNetCompiler
 2id: 9ccba514-7cb6-4c5c-b377-700758f2f120 # SuspChild
 3related:
 4    - id: 4c7f49ee-2638-43bb-b85b-ce676c30b260 # TMP File
 5      type: similar
 6    - id: 9f50fe98-fe5c-4a2d-86c7-fad7f63ed622 # Susp Paths
 7      type: similar
 8    - id: a01b8329-5953-4f73-ae2d-aa01e1f35f00 # Exec
 9      type: similar
10status: test
11description: Detects potentially suspicious child processes of "aspnet_compiler.exe".
12references:
13    - https://lolbas-project.github.io/lolbas/Binaries/Aspnet_Compiler/
14    - https://ijustwannared.team/2020/08/01/the-curious-case-of-aspnet_compiler-exe/
15author: Nasreddine Bencherchali (Nextron Systems)
16date: 2023-08-14
17tags:
18    - attack.execution
19    - attack.stealth
20    - attack.t1127
21logsource:
22    category: process_creation
23    product: windows
24detection:
25    selection_parent:
26        ParentImage|endswith: '\aspnet_compiler.exe'
27    selection_child:
28        # Note: add other potential suspicious child processes and paths
29        - Image|endswith:
30              - '\calc.exe'
31              - '\notepad.exe'
32        - Image|contains:
33              - '\Users\Public\'
34              - '\AppData\Local\Temp\'
35              - '\AppData\Local\Roaming\'
36              - ':\Temp\'
37              - ':\Windows\Temp\'
38              - ':\Windows\System32\Tasks\'
39              - ':\Windows\Tasks\'
40    condition: all of selection_*
41falsepositives:
42    - Unknown
43level: high