Remcos RAT File Creation in Remcos Folder
Description
The following analytic detects the creation of files in the Remcos folder within the AppData directory, specifically targeting keylog and clipboard log files. It leverages the Endpoint.Filesystem data model to identify .dat files created in paths containing "remcos." This activity is significant as it indicates the presence of the Remcos RAT, which performs keylogging, clipboard capturing, and audio recording. If confirmed malicious, this could lead to unauthorized data exfiltration and extensive surveillance capabilities for the attacker.
- Type: TTP
- Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Datamodel: Endpoint
- Last Updated: 2024-05-24
- Author: Teoderick Contreras, Splunk, Sanjay Govind
- ID: 25ae862a-1ac3-11ec-94a1-acde48001122
Annotations
Kill Chain Phase
- Exploitation
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
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|tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem where Filesystem.file_name IN ("*.dat") Filesystem.file_path = "*\\remcos\\*" by _time Filesystem.file_name Filesystem.file_path Filesystem.dest Filesystem.file_create_time
| `drop_dm_object_name(Filesystem)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `remcos_rat_file_creation_in_remcos_folder_filter`
Macros
The SPL above uses the following Macros:
remcos_rat_file_creation_in_remcos_folder_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
- dest
- file_create_time
- file_name
- file_path
How To Implement
To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.
Known False Positives
unknown
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
100.0 | 100 | 100 | file $file_name$ created in $file_path$ of $dest$ |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
- https://success.trendmicro.com/dcx/s/solution/1123281-remcos-malware-information?language=en_US
- https://blog.malwarebytes.com/threat-intelligence/2021/07/remcos-rat-delivered-via-visual-basic/
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: 3