Windows Snake Malware File Modification Crmlog
The following analytic identfies a .crmlog written to windows\registration. Per the report, typically, this file has been found within the %windows%\Registration directory with the format of <RANDOM_GUID>.<RANDOM_GUID>.crmlog and is decrypted by Snake's kernel driver.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2023-05-10
- Author: Michael Haag, Splunk
- ID: 27187e0e-c221-471d-a7bd-04f698985ff6
Kill Chain Phase
- CIS 10
1 2 3 4 5 6 | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Filesystem where Filesystem.file_path="*\\windows\\registration\\*" AND Filesystem.file_name="*.crmlog" by Filesystem.file_create_time Filesystem.process_id Filesystem.file_name Filesystem.file_path Filesystem.dest | `drop_dm_object_name(Filesystem)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_snake_malware_file_modification_crmlog_filter`
The SPL above uses the following Macros:
windows_snake_malware_file_modification_crmlog_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
List of fields required to use this analytic.
How To Implement
To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the
Endpoint datamodel in the
Filesystem node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.
Known False Positives
False positives may be present as the file pattern does match legitimate files on disk. It is possible other native tools write the same file name scheme.
Associated Analytic Story
|25.0||50||50||A file related to Snake Malware has been identified on $dest$.|
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
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source | version: 1