This search is to detect a suspicious enabling of smb1protocol through “powershell.exe”. This technique was seen in some ransomware (like reddot) where it enable smb share to do the lateral movement and encrypt other files within the compromise network system.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2021-06-22
- Author: Teoderick Contreras, Splunk
- ID: afed80b2-d34b-11eb-a952-acde48001122
Kill Chain Phase
1 2 3 4 5 `powershell` EventCode=4104 Message = "*Enable-WindowsOptionalFeature*" Message = "*SMB1Protocol*" | stats count min(_time) as firstTime max(_time) as lastTime by EventCode Message ComputerName User | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `powershell_enable_smb1protocol_feature_filter`
The SPL above uses the following Macros:
Note that powershell_enable_smb1protocol_feature_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
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
network operator may enable or disable this windows feature.
Associated Analytic story
|25.0||50||50||Powershell Enable SMB1Protocol Feature|
source | version: 1