LSASS dump via process access

Status: experimental
Severity: high
Log source: product windows, category process_access
Author: mdecrevoisier
Source: github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker attempt to dump LSASS process with tools like Mimikatz.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1003.001` OS Credential Dumping: LSASS Memory

Event coverage

Provider	Event	Title
Sysmon	Event ID 10	ProcessAccess

Rule body yaml

title: LSASS dump via process access
description: Detects scenarios where an attacker attempt to dump LSASS process with tools like Mimikatz.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0006-Credential%20Access/T1003-Credential%20dumping
- https://threathunterplaybook.com/notebooks/windows/06_credential_access/WIN-191030201010.html
- https://medium.com/threatpunter/detecting-attempts-to-steal-passwords-from-memory-558f16dce4ea
- https://cyberwardog.blogspot.com/2017/03/chronicles-of-threat-hunter-hunting-for_22.html
tags:
- attack.credential_access
- attack.t1003.001
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  category: process_access
detection:
  selection:
    EventID: 10 # process accessed
    TargetImage|endswith: '\system32\lsass.exe'
    GrantedAccess:
      - '0x1410'
      - '0x1010'
      - '0x1438' # could refers to misc::memssp
      - '0x143a'
      - '0x1418'
      - '0x1fffff' # ProcDump
  filter:
    SourceImage:
      - '*\ProgramData\Microsoft\Windows Defender\Platform\*'
      - '*\Program Files\Windows Defender Advanced Threat Protection\*'
      - '*\system32\csrss.exe'
      - '*\system32\wininit.exe'
  condition: selection and not filter
falsepositives:
- Antivirus, security products, browsers
level: high

Stages and Predicates

Stage 0: `condition`

selection and not filter

Stage 1: `selection`

selection:
  EventID: 10
  TargetImage|endswith: '\system32\lsass.exe'
  GrantedAccess:
    - '0x1410'
    - '0x1010'
    - '0x1438'
    - '0x143a'
    - '0x1418'
    - '0x1fffff'

Stage 2: `not filter`

filter:
  SourceImage:
    - '*\ProgramData\Microsoft\Windows Defender\Platform\*'
    - '*\Program Files\Windows Defender Advanced Threat Protection\*'
    - '*\system32\csrss.exe'
    - '*\system32\wininit.exe'

Exclusions

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

Field	Kind	Excluded values
`SourceImage`	ends_with	`\system32\csrss.exe`
`SourceImage`	ends_with	`\system32\wininit.exe`
`SourceImage`	match	`\Program Files\Windows Defender Advanced Threat Protection\`
`SourceImage`	match	`\ProgramData\Microsoft\Windows Defender\Platform\`

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
`GrantedAccess`	eq	`0x1010` corpus 2 (sigma 1, splunk 1) `0x1410` corpus 2 (sigma 1, splunk 1) `0x1418` `0x1438` `0x143a` corpus 2 (sigma 2) `0x1fffff` corpus 9 (sigma 7, splunk 1, kusto 1)
`TargetImage`	ends_with	`\system32\lsass.exe`

`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)

LSASS dump via process access

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

LSASS dump via process access

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`