Anomalous Usage of Account Credentials
THIS IS A EXPERIMENTAL DETECTION
This detection has been marked experimental by the Splunk Threat Research team. This means we have not been able to test, simulate, or build datasets for this detection. Use at your own risk. This analytic is NOT supported.
Description
This is an anomaly generating detection looking for multiple interactive logins within a specific time period. An insider threat may attempt to steal colleagues credentials in low tech, undetectable methods, in order to gain access to additional information or to hide their own behavior. This should capture their attempted use of those credentials on a workstation.
- Type: Anomaly
- Product: Splunk Behavioral Analytics
- Datamodel: Endpoint_Processes
- Last Updated: 2021-12-07
- Author: Lou Stella, Splunk
- ID: 629cbf9e-5785-11ec-9611-acde48001122
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
- PR.AC
- DE.AE
CIS20
- CIS 14
CVE
Search
1
2
3
4
5
6
7
8
9
10
11
| from read_ssa_enriched_events()
| eval device=ucast(map_get(input_event, "dest_device_id"), "string", null), auth_type=ucast(map_get(input_event, "authentication_type"), "string", null), timestamp=parse_long(ucast(map_get(input_event, "_time"), "string", null)), src_user=ucast(map_get(input_event, "dest_user_original_artifact"), "string", null), signature_id=ucast(map_get(input_event, "EventCode"), "string", null)
| where signature_id="4624"
| where auth_type="2" OR auth_type="11"
| where NOT (src_user="SYSTEM") AND NOT (src_user="ANONYMOUS LOGON")
| stats estdc(src_user) AS user_counter by device, span(timestamp, 600s, 300s)
| where user_counter>=2
| rename window_end AS timestamp
| eval start_time=window_start, end_time=timestamp, entities=mvappend(device), body=create_map(["user_counter", user_counter, "device", device])
| into write_ssa_detected_events();
Macros
The SPL above uses the following Macros:
anomalous_usage_of_account_credentials_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Required fields
List of fields required to use this analytic.
- _time
How To Implement
To successfully implement this detection, you need to be ingesting logon events from workstations.
Known False Positives
Shared workstations can cause false positives
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
6.0 | 20 | 30 | Multiple interactive logins detected on $device$ |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
Test Dataset
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 | version: 1