Potential Privilege Escalation To LOCAL SYSTEM

Detects unknown program using commandline flags usually used by tools such as PsExec and PAExec to start programs with SYSTEM Privileges

Sigma rule (View on GitHub)

 1title: Potential Privilege Escalation To LOCAL SYSTEM
 2id: 207b0396-3689-42d9-8399-4222658efc99
 3related:
 4    - id: 8834e2f7-6b4b-4f09-8906-d2276470ee23 # PsExec specific rule
 5      type: similar
 6status: test
 7description: Detects unknown program using commandline flags usually used by tools such as PsExec and PAExec to start programs with SYSTEM Privileges
 8references:
 9    - https://learn.microsoft.com/en-us/sysinternals/downloads/psexec
10    - https://www.poweradmin.com/paexec/
11    - https://www.fireeye.com/blog/threat-research/2020/10/kegtap-and-singlemalt-with-a-ransomware-chaser.html
12author: Florian Roth (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
13date: 2021-05-22
14modified: 2024-03-05
15tags:
16    - attack.resource-development
17    - attack.t1587.001
18logsource:
19    category: process_creation
20    product: windows
21detection:
22    selection:
23        # Escalation to LOCAL_SYSTEM
24        CommandLine|contains|windash:
25            # Note that you don't need to add the ".exe" part when using psexec/paexec
26            # The "-" can also be replaced with "/"
27            # The order of args isn't important
28            # "cmd" can be replaced by "powershell", "pwsh" or any other console like software
29            - ' -s cmd'
30            - ' -s -i cmd'
31            - ' -i -s cmd'
32            # Pwsh (For PowerShell 7)
33            - ' -s pwsh'
34            - ' -s -i pwsh'
35            - ' -i -s pwsh'
36            # PowerShell (For PowerShell 5)
37            - ' -s powershell'
38            - ' -s -i powershell'
39            - ' -i -s powershell'
40    filter_main_exclude_coverage:
41        # This filter exclude strings covered by 8834e2f7-6b4b-4f09-8906-d2276470ee23
42        CommandLine|contains:
43            - 'paexec'
44            - 'PsExec'
45            - 'accepteula'
46    condition: selection and not 1 of filter_main_*
47falsepositives:
48    - Weird admins that rename their tools
49    - Software companies that bundle PsExec/PAExec with their software and rename it, so that it is less embarrassing
50level: high

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