Detection rules › YARA-L

sap multi terminal logon

Severity
medium
Time window
15m
Match by
user
Author
Google Cloud Security
Source
github.com/chronicle/detection-rules

Identifies successful logons for the same User ID from multiple different terminal IDs or client hostnames in a short timeframe, indicating potential credential sharing or session theft.

MITRE ATT&CK coverage

TacticTechniques
Initial Access
Persistence
Privilege Escalation
Stealth

Telemetry coverage

Rule body

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

rule sap_multi_terminal_logon {

  meta:
    author = "Google Cloud Security"
    description = "Identifies successful logons for the same User ID from multiple different terminal IDs or client hostnames in a short timeframe, indicating potential credential sharing or session theft."
    severity = "medium"
    tactic = "TA0006"
    technique = "T1078"

  events:
    $e.metadata.log_type = "SAP_SECURITY_AUDIT"
    (
        $e.metadata.event_type = "USER_LOGIN" or
        $e.additional.fields["msg_1"] = /^AU1$|^AU5$/
    )


    // Ensure we only check events that actually have a terminal/hostname recorded
    $e.principal.hostname != ""

    $terminal = $e.principal.hostname
    $user = $e.principal.user.userid

  match:
    // You can reduce this window to 15m or 30m if 1h is too broad for direct terminal switches
    $user over 15m

  outcome:
    $terminals = array_distinct($terminal)
    $count_of_terminals = count_distinct($terminal)
    // Give a high risk score if they switch terminals
    $risk_score = 60
    $sap_instance = array_distinct($e.target.resource.name)

  condition:
    // Trigger if the user is seen on 2 or more distinct terminals
    #terminal >= 2
}

YARA-L rule structure

Condition

Fires when $terminal occurs at least 2 times in the 15m window.

Events

$e USER_LOGIN (4624, 4625, 4648)

  • metadata.log_type = "SAP_SECURITY_AUDIT"
  • additional.fields["msg_1"] matches "^AU1$|^AU5$"
  • principal.hostname is not null

Match and correlation

Match key
$user
Within
15m

Outcome

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

FieldExpression
terminalsarray_distinct($terminal)
count_of_terminalscount_distinct($terminal)
risk_score60
sap_instancearray_distinct($e.target.resource.name)