Detectionmediumtest

New or Renamed User Account with '$' Character

Detects the creation of a user with the "$" character. This can be used by attackers to hide a user or trick detection systems that lack the parsing mechanisms.

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Launch
Ilyas Ochkov, oscd.communityCreated Fri Oct 25Updated Tue Jan 16cfeed607-6aa4-4bbd-9627-b637deb723c8windows
Log Source
Windowssecurity
ProductWindows← raw: windows
Servicesecurity← raw: security
Detection Logic
Detection Logic3 selectors
detection:
    selection_create:
        EventID: 4720 # create user
        SamAccountName|contains: '$'
    selection_rename:
        EventID: 4781 # rename user
        NewTargetUserName|contains: '$'
    filter_main_homegroup:
        EventID: 4720
        TargetUserName: 'HomeGroupUser$'
    condition: 1 of selection_* and not 1 of filter_main_*
False Positives
Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

Rule Metadata
Rule ID
cfeed607-6aa4-4bbd-9627-b637deb723c8
Status
test
Level
medium
Type
Detection
Created
Fri Oct 25
Modified
Tue Jan 16
Path
rules/windows/builtin/security/win_security_new_or_renamed_user_account_with_dollar_sign.yml
Raw Tags
attack.defense-evasionattack.t1036
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