Subvert Trust Controls: Install Root Certificate T1553.004
Tactic: Defense Impairment
Adversaries may install a root certificate on a compromised system to avoid warnings when connecting to adversary controlled web servers. Root certificates are used in public key cryptography to identify a root certificate authority (CA). When a root certificate is installed, the system or application will trust certificates in the root's chain of trust that have been signed by the root certificate. Certificates are commonly used for establishing secure TLS/SSL communications within a web browser. When a user attempts to browse a website that presents a certificate that is not trusted an error message will be displayed to warn the user of the security risk. Depending on the security settings, the browser may not allow the user to establish a connection to the website.
Events covered
8 catalog events are tagged with this technique by at least one rule.
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Sysmon | Event ID 12 | RegistryEvent (Object create and delete) |
| Sysmon | Event ID 13 | RegistryEvent (Value Set) |
| Sysmon | Event ID 14 | RegistryEvent (Key and Value Rename) |
| Security-Auditing | Event ID 4688 | A new process has been created. |
| CertificationAuthority | Event ID 53 | Active Directory Certificate Services denied request Name because RequestId. |
| PowerShell | Event ID 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
| Sysmon-for-Linux | Event ID 1 | Process Create |
Authoring guide
Patterns shared across the 17 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.
Fields filtered most (21 distinct)
The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.
Top indicator values (96 distinct)
Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique. Click a value to expand the rules under this technique that use it.
Exclusions (59 distinct)
Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths. Click a value to expand the rules under this technique that exclude it.
Rules under this technique
Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.
Sigma 11 rules
- Active Directory Certificate Services Denied Certificate Enrollment Request
- Certutil root certificate installation
- Cisco Crypto Commands
- Install Root Certificate
- New Root Certificate Installed Via CertMgr.EXE
- New Root Certificate Installed Via Certutil.EXE
- Root Certificate Installed - PowerShell
- Root Certificate Installed From Susp Locations
- Suspicious Package Installed - Linux
- Suspicious X509Enrollment - Process Creation
- Suspicious X509Enrollment - Ps Script
Elastic 3 rules
- Attempt to Install Root Certificate
- Creation or Modification of Root Certificate
- Root Certificate Installation