Shared folder access with forged Golden ticket

Status: stable
Severity: high
Log source: product windows, service security
Author: mdecrevoisier
Source: github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker used a forged Golden ticket to login on a remote shared folder. Per default or if specified, the ticket will be forged using the builtin administrator account (SID *-500). However, and it frequent cases, a non suspicious user name will be specificied during the forge in order to evade security monitoring. The rule works based on this trick.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1558.001` Steal or Forge Kerberos Tickets: Golden Ticket

Event coverage

Provider	Event	Title
Security-Auditing	Event ID 5140	A network share object was accessed.
Security-Auditing	Event ID 5145	A network share object was checked to see whether client can be granted desired access.

Rule body yaml

title: Shared folder access with forged Golden ticket
description: Detects scenarios where an attacker used a forged Golden ticket to login on a remote shared folder. Per default or if specified, the ticket will be forged using the builtin administrator account (SID *-500). However, and it frequent cases, a non suspicious user name will be specificied during the forge in order to evade security monitoring. The rule works based on this trick.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0006-Credential%20Access/T1558-Steal%20or%20Forge%20Kerberos%20Tickets
- https://infosecwriteups.com/forest-an-asreproast-dcsync-and-golden-ticket-hackthebox-walkthrough-ade8dcdd1ee5
- https://attack.stealthbits.com/how-golden-ticket-attack-works
- https://www.hackingarticles.in/domain-persistence-golden-ticket-attack/
- https://adsecurity.org/?p=1515
- https://en.it-pirate.eu/azure-atp-golden-ticket-attack-how-golden-ticket-attacks-work/
- https://www.ired.team/offensive-security-experiments/active-directory-kerberos-abuse/kerberos-golden-tickets
- https://bond-o.medium.com/golden-ticket-attack-ea89553cf9c0
- https://social.technet.microsoft.com/wiki/contents/articles/13813.localized-names-for-administrator-account-in-windows.aspx
- https://www.blackhat.com/docs/us-15/materials/us-15-Metcalf-Red-Vs-Blue-Modern-Active-Directory-Attacks-Detection-And-Protection-wp.pdf
tags:
- attack.credential_access
- attack.t1558.001
author: mdecrevoisier
status: stable
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID:
      - 5140
      - 5145
    SubjectUserSid|startswith: 'S-1-5-21'
    SubjectUserSid|endswith: '-500' # Refers to builtin Administrator SID account
  filter:
    SubjectUserName: # Excludes builtin admin account names when using a localized Windows OS version (select the ones applicable)
      - 'Administrator'  # Default
      - 'Järjestelmänvalvoja' # Finnish
      - 'Administrateur' # French
      - 'Administrador'  # Spanish / Portuguese
      - 'Administratör'  # Swedish
      - 'Rendszergazda'  # Hungarian
      - 'Администратор'  # Russian
  condition: selection and not filter
falsepositives:
- login with renamed builtin administrator account ("administrator" renamed to "admin_org")
level: high

Stages and Predicates

Stage 0: `condition`

selection and not filter

Stage 1: `selection`

selection:
  EventID:
    - 5140
    - 5145
  SubjectUserSid|startswith: 'S-1-5-21'
  SubjectUserSid|endswith: '-500'

Stage 2: `not filter`

filter:
  SubjectUserName:
    - 'Administrator'
    - 'Järjestelmänvalvoja'
    - 'Administrateur'
    - 'Administrador'
    - 'Administratör'
    - 'Rendszergazda'
    - 'Администратор'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`SubjectUserName`	eq	`Administrador`
`SubjectUserName`	eq	`Administrateur`
`SubjectUserName`	eq	`Administrator`
`SubjectUserName`	eq	`Administratör`
`SubjectUserName`	eq	`Järjestelmänvalvoja`
`SubjectUserName`	eq	`Rendszergazda`
`SubjectUserName`	eq	`Администратор`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`SubjectUserSid`	ends_with	`-500`
`SubjectUserSid`	starts_with	`S-1-5-21` corpus 2 (sigma 1, elastic 1)

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

Shared folder access with forged Golden ticket

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection`

Stage 2: `not filter`

Exclusions

Indicators

Keyboard shortcuts

Search operators

Shared folder access with forged Golden ticket

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection

Stage 2: not filter

Exclusions

Indicators

Stage 0: `condition`

Stage 1: `selection`

Stage 2: `not filter`