User Added to Local Administrators Group

 1title: User Added to Local Administrators Group
 2id: ad720b90-25ad-43ff-9b5e-5c841facc8e5
 3related:
 4    - id: ffa28e60-bdb1-46e0-9f82-05f7a61cc06e # Remote Desktop groups
 5      type: similar
 6    - id: 10fb649c-3600-4d37-b1e6-56ea90bb7e09 # Privileged groups
 7      type: similar
 8status: test
 9description: Detects addition of users to the local administrator group via "Net" or "Add-LocalGroupMember".
10references:
11    - https://blog.talosintelligence.com/2022/08/recent-cyber-attack.html?m=1
12author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
13date: 2022-08-12
14modified: 2023-03-02
15tags:
16    - attack.privilege-escalation
17    - attack.persistence
18    - attack.t1098
19logsource:
20    category: process_creation
21    product: windows
22detection:
23    selection_main:
24        - CommandLine|contains|all:
25              # net.exe
26              - 'localgroup '
27              - ' /add'
28        - CommandLine|contains|all:
29              # powershell.exe
30              - 'Add-LocalGroupMember '
31              - ' -Group '
32    selection_group:
33        CommandLine|contains:
34            - ' administrators '
35            - ' administrateur' # Typo without an 'S' so we catch both
36    condition: all of selection_*
37falsepositives:
38    - Administrative activity
39level: medium