Detection rules › YARA-L

Process Memory Dump via RdrLeakDiag.exe

Severity
high
Type
Detection
Time window
5m
Match by
hostname
Author
Cedric MAURUGEON, Florian Roth (Nextron Systems), Swachchhanda Shrawan Poudel, Nasreddine Bencherchali (Nextron Systems)
Source
github.com/chronicle/detection-rules

Detects the use of the Microsoft Windows Resource Leak Diagnostic tool rdrleakdiag.exe to dump process memory

Known false positives

  • Unlikely

MITRE ATT&CK coverage

TacticTechniques
Credential Access

References

Telemetry coverage

Rule body

// Copyright 2025 Google LLC. Licensed under Apache-2.0.

rule process_memory_dump_via_rdrleakdiag {

  meta:
    author = "Cedric MAURUGEON, Florian Roth (Nextron Systems), Swachchhanda Shrawan Poudel, Nasreddine Bencherchali (Nextron Systems)"
    description = "Detects the use of the Microsoft Windows Resource Leak Diagnostic tool rdrleakdiag.exe to dump process memory"
    reference = "https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_rdrleakdiag_process_dumping.yml"
    license = "https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md"
    rule_name = "Process Memory Dump via RdrLeakDiag.exe"
    sigma_uuid = "edadb1e5-5919-4e4c-8462-a9e643b02c4b"
    sigma_status = "test"
    rule_id = "mr_89eca7b6-5b7e-4bd1-978e-156bd00f5324"
    tactic = "TA0006"
    technique = "T1003.001"
    type = "Detection"
    data_source = "Windows Event Logs"
    platform = "Windows"
    severity = "High"
    priority = "High"
    false_positives = "Unlikely"

  events:
    $process.metadata.event_type = "PROCESS_LAUNCH"
    (
        re.regex($process.target.process.file.full_path, `rdrleakdiag\.exe$`) nocase or
        $process.src.process.file.full_path = "RdrLeakDiag.exe" nocase
    )
    re.regex($process.target.process.command_line, `(/|full)memdmp`) nocase
    re.regex($process.target.process.command_line, `/(o|p)`) nocase

    $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
}

YARA-L rule structure

Condition

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

Events

$process PROCESS_LAUNCH (1, 4688)

  • target.process.file.full_path matches "rdrleakdiag\.exe$"
  • src.process.file.full_path = "RdrLeakDiag.exe"
  • target.process.command_line matches "(/|full)memdmp"
  • target.process.command_line matches "/(o|p)"

Match and correlation

Match key
$hostname (principal.hostname)
Within
5m

Outcome

Outcome variables add context to a detection. When the rule generates an alert, $risk_score is displayed with it.

FieldExpression
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))