Detection rules › Splunk
Detect Remote Access Software Usage File
The following analytic detects the writing of files from known remote access software to disk within the environment. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on file path, file name, and user information. This activity is significant as adversaries often use remote access tools like AnyDesk, GoToMyPC, LogMeIn, and TeamViewer to maintain unauthorized access. If confirmed malicious, this could allow attackers to persist in the environment, potentially leading to data exfiltration, further compromise, or complete control over affected systems. It is best to update both the remote_access_software_usage_exception.csv lookup and the remote_access_software lookup with any known or approved remote access software to reduce false positives and increase coverage. In order to enhance performance, the detection filters for specific file names extensions / names that are used in the remote_access_software lookup. If add additional entries, consider updating the search filters to include those file names / extensions as well, if not alread covered.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control | T1219 Remote Access Tools |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 11 | FileCreate |
Stages and Predicates
Stage 1: tstats
tstats WHERE Filesystem.file_name IN ("*.app", "*.exe", "*.msi", "*.pkg", "*Idrive.*", "*echoware.dll", "*rdp2tcp.py") BY Filesystem.action, Filesystem.dest, Filesystem.file_access_time, Filesystem.file_create_time, Filesystem.file_hash, Filesystem.file_modify_time, Filesystem.file_name, Filesystem.file_path, Filesystem.file_acl, Filesystem.file_size, Filesystem.process_guid, Filesystem.process_id, Filesystem.user, Filesystem.vendor_product
Stage 2: search
search
Stage 3: search
search
Stage 4: search
search
Stage 5: lookup
lookup <lookup> category, comment_reference, desc, description, file_name, isutility, remote_utility, signature
Stage 6: search
search isutility=TRUE
Stage 7: search
search `macro`
Stage 8: search
search `macro`
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Filesystem.file_name | in |
|
isutility | eq |
|