Detection rules › YARA-L

HackTool - Mimikatz Execution

Severity
high
Type
Detection
Time window
5m
Match by
hostname
Source
github.com/chronicle/detection-rules

Detection well-known mimikatz command line arguments

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1003.001 OS Credential Dumping: LSASS Memory

References

Event coverage

Rule body yaral

/*
 * Copyright 2025 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

rule hacktool_mimikatz_execution {

  meta:
    author = "Teymur Kheirkhabarov, oscd.community, David ANDRE (additional keywords), Tim Shelton"
    description = "Detection well-known mimikatz command line arguments"
    reference = "https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_hktl_mimikatz_command_line.yml"
    license = "https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md"
    rule_name = "HackTool - Mimikatz Execution"
    sigma_uuid = "a642964e-bead-4bed-8910-1bb4d63e3b4d"
    sigma_status = "test"
    rule_id = "mr_d173bc90-2dcf-418d-a40c-bb7792f6300a"
    tactic = "TA0006"
    technique = "T1003.001"
    type = "Detection"
    data_source = "Sysmon"
    platform = "Windows"
    severity = "High"
    priority = "High"
    false_positives = "Unlikely"

  events:
    $process.metadata.event_type = "PROCESS_LAUNCH"
    (
        strings.contains(strings.to_lower($process.target.process.command_line), "dumpcreds") or
        strings.contains(strings.to_lower($process.target.process.command_line), "mimikatz") or
        strings.contains(strings.to_lower($process.target.process.command_line), "::aadcookie") or
        strings.contains(strings.to_lower($process.target.process.command_line), "::detours") or
        strings.contains(strings.to_lower($process.target.process.command_line), "::memssp") or
        strings.contains(strings.to_lower($process.target.process.command_line), "::mflt") or
        strings.contains(strings.to_lower($process.target.process.command_line), "::ncroutemon") or
        strings.contains(strings.to_lower($process.target.process.command_line), "::ngcsign") or
        strings.contains(strings.to_lower($process.target.process.command_line), "::printnightmare") or
        strings.contains(strings.to_lower($process.target.process.command_line), "::skeleton") or
        strings.contains(strings.to_lower($process.target.process.command_line), "::preshutdown") or
        strings.contains(strings.to_lower($process.target.process.command_line), "::mstsc") or
        strings.contains(strings.to_lower($process.target.process.command_line), "::multirdp") or
        strings.contains(strings.to_lower($process.target.process.command_line), "rpc::") or
        strings.contains(strings.to_lower($process.target.process.command_line), "token::") or
        strings.contains(strings.to_lower($process.target.process.command_line), "crypto::") or
        strings.contains(strings.to_lower($process.target.process.command_line), "dpapi::") or
        strings.contains(strings.to_lower($process.target.process.command_line), "sekurlsa::") or
        strings.contains(strings.to_lower($process.target.process.command_line), "kerberos::") or
        strings.contains(strings.to_lower($process.target.process.command_line), "lsadump::") or
        strings.contains(strings.to_lower($process.target.process.command_line), "privilege::") or
        strings.contains(strings.to_lower($process.target.process.command_line), "process::") or
        strings.contains(strings.to_lower($process.target.process.command_line), "vault::")
    )
    $process.principal.hostname = $hostname

  match:
    $hostname over 5m

  outcome:
    //example usage of specifying test user and hostname to adjust risk score
    $risk_score = max(if($process.principal.user.userid = "user" and $process.principal.hostname = "hostname", 0, 15))
    $principal_process_pid = array_distinct($process.principal.process.pid)
    $principal_process_command_line = array_distinct($process.principal.process.command_line)
    $principal_process_file_sha256 = array_distinct($process.principal.process.file.sha256)
    $principal_process_file_full_path = array_distinct($process.principal.process.file.full_path)
    $principal_process_product_specfic_process_id = array_distinct($process.principal.process.product_specific_process_id)
    $principal_process_parent_process_product_specfic_process_id = array_distinct($process.principal.process.parent_process.product_specific_process_id)
    $target_process_pid = array_distinct($process.target.process.pid)
    $target_process_command_line = array_distinct($process.target.process.command_line)
    $target_process_file_sha256 = array_distinct($process.target.process.file.sha256)
    $target_process_file_full_path = array_distinct($process.target.process.file.full_path)
    $target_process_product_specfic_process_id = array_distinct($process.target.process.product_specific_process_id)
    $principal_user_userid = array_distinct($process.principal.user.userid)
    $log_type = array_distinct(strings.concat($process.metadata.log_type,"/",$process.metadata.product_event_type))

  condition:
    $process
}

Stages and Predicates

Stage 0: match + condition

match:
    $hostname over 5m
condition:
    $process

Fires when at least one $process event in the 5m window.

Stage 1: events: $process · PROCESS_LAUNCH

$process.metadata.event_type = "PROCESS_LAUNCH"
(
    strings.contains(strings.to_lower($process.target.process.command_line), "dumpcreds") or
    strings.contains(strings.to_lower($process.target.process.command_line), "mimikatz") or
    strings.contains(strings.to_lower($process.target.process.command_line), "::aadcookie") or
    strings.contains(strings.to_lower($process.target.process.command_line), "::detours") or
    strings.contains(strings.to_lower($process.target.process.command_line), "::memssp") or
    strings.contains(strings.to_lower($process.target.process.command_line), "::mflt") or
    strings.contains(strings.to_lower($process.target.process.command_line), "::ncroutemon") or
    strings.contains(strings.to_lower($process.target.process.command_line), "::ngcsign") or
    strings.contains(strings.to_lower($process.target.process.command_line), "::printnightmare") or
    strings.contains(strings.to_lower($process.target.process.command_line), "::skeleton") or
    strings.contains(strings.to_lower($process.target.process.command_line), "::preshutdown") or
    strings.contains(strings.to_lower($process.target.process.command_line), "::mstsc") or
    strings.contains(strings.to_lower($process.target.process.command_line), "::multirdp") or
    strings.contains(strings.to_lower($process.target.process.command_line), "rpc::") or
    strings.contains(strings.to_lower($process.target.process.command_line), "token::") or
    strings.contains(strings.to_lower($process.target.process.command_line), "crypto::") or
    strings.contains(strings.to_lower($process.target.process.command_line), "dpapi::") or
    strings.contains(strings.to_lower($process.target.process.command_line), "sekurlsa::") or
    strings.contains(strings.to_lower($process.target.process.command_line), "kerberos::") or
    strings.contains(strings.to_lower($process.target.process.command_line), "lsadump::") or
    strings.contains(strings.to_lower($process.target.process.command_line), "privilege::") or
    strings.contains(strings.to_lower($process.target.process.command_line), "process::") or
    strings.contains(strings.to_lower($process.target.process.command_line), "vault::")
)
$process.principal.hostname = $hostname

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.

FieldKindValues
target.process.command_linecontains
  • ::aadcookie transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • ::detours transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • ::memssp transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • ::mflt transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • ::mstsc transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • ::multirdp transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • ::ncroutemon transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • ::ngcsign transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • ::preshutdown transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • ::printnightmare transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • ::skeleton transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • crypto:: transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • dpapi:: transforms: tolower corpus 3 (sigma 2, chronicle 1)
  • dumpcreds transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • kerberos:: transforms: tolower corpus 3 (sigma 2, chronicle 1)
  • lsadump:: transforms: tolower corpus 3 (sigma 2, chronicle 1)
  • mimikatz transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • privilege:: transforms: tolower corpus 3 (sigma 2, chronicle 1)
  • process:: transforms: tolower corpus 2 (sigma 1, chronicle 1)
  • rpc:: transforms: tolower corpus 3 (sigma 2, chronicle 1)
  • sekurlsa:: transforms: tolower corpus 3 (sigma 2, chronicle 1)
  • token:: transforms: tolower corpus 3 (sigma 2, chronicle 1)
  • vault:: transforms: tolower corpus 2 (sigma 1, chronicle 1)

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

FieldSource
risk_scoremax(if($process.principal.user.userid = "user" and $process.principal.hostname = "hostname", 0, 15))
principal_process_pidarray_distinct($process.principal.process.pid)
principal_process_command_linearray_distinct($process.principal.process.command_line)
principal_process_file_sha256array_distinct($process.principal.process.file.sha256)
principal_process_file_full_patharray_distinct($process.principal.process.file.full_path)
principal_process_product_specfic_process_idarray_distinct($process.principal.process.product_specific_process_id)
principal_process_parent_process_product_specfic_process_idarray_distinct($process.principal.process.parent_process.product_specific_process_id)
target_process_pidarray_distinct($process.target.process.pid)
target_process_command_linearray_distinct($process.target.process.command_line)
target_process_file_sha256array_distinct($process.target.process.file.sha256)
target_process_file_full_patharray_distinct($process.target.process.file.full_path)
target_process_product_specfic_process_idarray_distinct($process.target.process.product_specific_process_id)
principal_user_useridarray_distinct($process.principal.user.userid)
log_typearray_distinct(strings.concat($process.metadata.log_type,"/",$process.metadata.product_event_type))