Allow Inbound Traffic In Firewall Rule
Description
The following analytic identifies suspicious PowerShell command to allow inbound traffic inbound to a specific local port within the public profile. This technique was seen in some attacker want to have a remote access to a machine by allowing the traffic in firewall rule.
- Type: TTP
-
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2021-05-19
- Author: Teoderick Contreras, Splunk
- ID: a5d85486-b89c-11eb-8267-acde48001122
Annotations
ATT&CK
Kill Chain Phase
- Exploitation
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
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`powershell` EventCode=4104 Message = "*firewall*" Message = "*Inbound*" Message = "*Allow*" Message = "*-LocalPort*"
| stats count min(_time) as firstTime max(_time) as lastTime by EventCode Message ComputerName User
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `allow_inbound_traffic_in_firewall_rule_filter`
Macros
The SPL above uses the following Macros:
allow_inbound_traffic_in_firewall_rule_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
- EventCode
- Message
- ComputerName
- User
How To Implement
To successfully implement this search, you need to be ingesting logs with the powershell logs from your endpoints. make sure you enable needed registry to monitor this event.
Known False Positives
administrator may allow inbound traffic in certain network or machine.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
3.0 | 10 | 30 | Suspicious firewall modification detected on endpoint $ComputerName$ by user $user$. |
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