Detection rules › YARA-L

sap gateway acl bypass attempt

Severity
low
Time window
30m
Match by
source_ip
Author
Google Cloud Security
Source
github.com/chronicle/detection-rules

Detects rejected connections by Gateway ACLs (secinfo/reginfo), indicating an attempt to bypass network-layer security.

MITRE ATT&CK coverage

TacticTechniques
Initial Access

Rule body

// Copyright 2026 Google LLC. Licensed under Apache-2.0.

rule sap_gateway_acl_bypass_attempt {

  meta:
    author = "Google Cloud Security"
    description = "Detects rejected connections by Gateway ACLs (secinfo/reginfo), indicating an attempt to bypass network-layer security."
    severity = "Low"
    tactic = "TA0001"
    technique = "T1190"

  events:
    $e.metadata.product_name = "SAP_GATEWAY"

    $e.additional.fields["event_action"] = /secinfo|reginfo/ nocase

    $e.security_result.action = "BLOCK"

    $source_ip = $e.principal.ip

  match:
    $source_ip over 30m

  outcome:
    $risk_score = 5
    $acl_type = array_distinct($e.additional.fields["event_action"])
    $attempted_programs = array_distinct($e.target.process.file.full_path)
    $error_details = array_distinct($e.security_result.description)
    $user_context = array_distinct($e.principal.user.userid)
    $total_denials = count($e.metadata.product_log_id)

  condition:
    $e
}

YARA-L rule structure

Condition

Fires when at least one $e event in the 30m window.

Events

$e

  • additional.fields["event_action"] matches "secinfo|reginfo"
  • security_result.action = "BLOCK"

Match and correlation

Match key
$source_ip
Within
30m

Outcome

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

FieldExpression
risk_score5
acl_typearray_distinct($e.additional.fields["event_action"])
attempted_programsarray_distinct($e.target.process.file.full_path)
error_detailsarray_distinct($e.security_result.description)
user_contextarray_distinct($e.principal.user.userid)
total_denialscount($e.metadata.product_log_id)