HackTool - Generic Process Access

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 * 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_generic_process_access {

  meta:
    author = "Nasreddine Bencherchali (Nextron Systems), Swachchhanda Shrawan Poudel"
    description = "Detects process access requests from hacktool processes based on their default image name"
    reference = "https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_access/proc_access_win_hktl_generic_access.yml"
    license = "https://github.com/SigmaHQ/Detection-Rule-License/blob/main/LICENSE.Detection.Rules.md"
    rule_name = "HackTool - Generic Process Access"
    sigma_uuid = "d0d2f720-d14f-448d-8242-51ff396a334e"
    sigma_status = "test"
    rule_id = "mr_1e8861fd-060a-4162-8e00-fa2b2a27e1e2"
    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_OPEN"
    (
        //reference lists for this rule are found in the reference_lists folder in community
        $process.principal.process.file.full_path IN regex %hacktool_regex nocase or
        $process.principal.process.file.full_path IN regex %hacktool_contains nocase
    )
    $process.principal.hostname = $hostname

  match:
    $hostname over 5m

  outcome:
    //example usage of specifying test hostname to adjust risk score
    $risk_score = max(if($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)
    $log_type = array_distinct(strings.concat($process.metadata.log_type,"/",$process.metadata.product_event_type))

  condition:
    $process
}