Detection: Cisco IOS Suspicious Privileged Account Creation

Updated Date: 2025-08-21 ID: 63e3aff9-45d7-4d41-bcdb-9da561fb4533 Author: Bhavin Patel, Michael Haag, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

This analytic detects the creation of privileged user accounts on Cisco IOS devices, which could indicate an attacker establishing backdoor access. The detection focuses on identifying when user accounts are created with privilege level 15 (the highest administrative privilege level in Cisco IOS) or when existing accounts have their privileges elevated. This type of activity is particularly concerning when performed by unauthorized users or during unusual hours, as it may represent a key step in establishing persistence following the exploitation of vulnerabilities like CVE-2018-0171 in Cisco Smart Install. Threat actors like Static Tundra have been observed creating privileged accounts as part of their attack chain after gaining initial access to network devices.

Search

1
2| tstats `security_content_summariesonly` count values(All_Changes.command) as command min(_time) as firstTime max(_time) as lastTime from datamodel=Change.All_Changes where ( (All_Changes.command="*username * privilege 15*") OR (All_Changes.command="*username * password*" AND All_Changes.command="*USER TABLE MODIFIED*") OR (All_Changes.command="*USER_PRIVILEGE_UPDATE*priv-15*") ) by All_Changes.dvc All_Changes.user 
3| `drop_dm_object_name("All_Changes")` 
4| rename dvc as dest 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `cisco_ios_suspicious_privileged_account_creation_filter`

Data Source

Name	Platform	Sourcetype	Source
Cisco IOS Logs	N/A	`'cisco:ios'`	`'cisco:ios'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
cisco_ios_suspicious_privileged_account_creation_filter	`search *`

cisco_ios_suspicious_privileged_account_creation_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1136	Create Account	Persistence
T1078	Valid Accounts	Defense Evasion

Delivery

Exploitation

Installation

DE.AE

CIS 13

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Risk Event	True

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

To implement this search, you need to be ingesting Cisco IOS logs with the sourcetype "cisco:ios" and have these logs mapped to the Change datamodel, with AAA accounting and command logging enabled on your Cisco devices.

Known False Positives

Legitimate account creation and privilege elevation activities by authorized administrators will generate alerts with this detection. To reduce false positives, consider implementing a baseline of expected administrative activities, including approved administrative usernames, typical times for account management, and authorized administrators who regularly perform these actions. You may also want to create a lookup table of approved administrative accounts and filter out alerts for these accounts. Additionally, scheduled maintenance windows should be taken into account when evaluating alerts.

Associated Analytic Story

Cisco Smart Install Remote Code Execution CVE-2018-0171

Risk Based Analytics (RBA)

Risk Message:

A suspicious privileged account was created or modified on Cisco IOS device $dest$ by user $user$

Risk Object	Risk Object Type	Risk Score	Threat Objects
user	user	50	command
dest	system	50	command

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`cisco:ios`	`cisco:ios`
Integration	✅ Passing	Dataset	`cisco:ios`	`cisco:ios`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 1