Adversaries may add their own root certificate to the certificate store, to cause the web browser to trust that certificate and not display a security warning when it encounters the previously unseen certificate. This action may be the precursor to malicious activity.

ATT&CK Detection

Technique Subtechnique(s) Tactic(s) Level of Coverage
Subvert Trust Controls Install Root Certificate Defense Evasion Moderate

Data Model References

Object Action Field
process create exe
process create command_line

Applicable Sensors

Implementations

Splunk code (Splunk, Endpoint)

You must be ingesting data that records process activity from your hosts to populate the Endpoint data model in the Processes node. You must also be ingesting logs with both the process name and command line from your endpoints. The command-line arguments are mapped to the “process” field in the Endpoint data model.

| tstats count min(_time) as firstTime values(Processes.process) as process max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name=*certutil* (Processes.process=*-addstore*) by Processes.parent_process Processes.process_name Processes.user

Pseudocode – detect attempts to add a certificate to a certificate store (Pseudocode, CAR native)

Pseudocode implementation of the splunk search below

processes = search Process:Create
addstore_commands = filter processes where (
  exe =”C:\Windows\System32\certutil.exe” AND command_line="*-addstore*” )
output addstore_commands

Unit Tests

Test Case 1

Configurations: Using Splunk Attack Range

Replay the detection dataset using the Splunk attack range with the commands below

python attack_range.py replay -dn data_dump [--dump NAME_OF_DUMP]

Test Case 2

Configurations: Using Invoke-AtomicRedTeam

execute the atomic test T1553.004 against a Windows target.

Invoke-AtomicTest T1553.004