Sigma Rule Library

Suspicious Connection to Remote Account

Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts. Without knowledge of the password for an account, an adversary may opt to systematically guess the password using a repetitive or iterative mechanism

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Detection logic

selection

ScriptBlockText|contains:
  - System.DirectoryServices.Protocols.LdapDirectoryIdentifier
  - System.Net.NetworkCredential
  - System.DirectoryServices.Protocols.LdapConnection

Condition

selection

Raw YAML

title: Suspicious Connection to Remote Account
id: 1883444f-084b-419b-ac62-e0d0c5b3693f
status: test
description: |
    Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts.
    Without knowledge of the password for an account, an adversary may opt to systematically guess the password using a repetitive or iterative mechanism
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1110.001/T1110.001.md#atomic-test-2---brute-force-credentials-of-single-active-directory-domain-user-via-ldap-against-domain-controller-ntlm-or-kerberos
author: frack113
date: 2021-12-27
tags:
    - attack.credential-access
    - attack.t1110.001
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection:
        ScriptBlockText|contains:
            - 'System.DirectoryServices.Protocols.LdapDirectoryIdentifier'
            - 'System.Net.NetworkCredential'
            - 'System.DirectoryServices.Protocols.LdapConnection'
    condition: selection
falsepositives:
    - Unknown
level: low

False positives

  • Unknown

References

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