Masquerading: Invalid Code Signature T1036.001
Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool. Code signing provides a level of authenticity on a binary from the developer and a guarantee that the binary has not been tampered with. Adversaries can copy the metadata and signature information from a signed program, then use it as a template for an unsigned program. Files with invalid code signatures will fail digital signature validation checks, but they may appear more legitimate to users and security tools may improperly handle these files.
Events covered
5 catalog events are tagged with this technique by at least one rule.
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Sysmon | Event ID 6 | Driver loaded |
| Sysmon | Event ID 7 | Image loaded |
| Security-Auditing | Event ID 4688 | A new process has been created. |
| Defender-DeviceProcessEvents | ProcessCreated | Process created |
Authoring guide
Patterns shared across the 15 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 (24 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 (966 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 (106 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.
Elastic 14 rules
- Expired or Revoked Driver Loaded
- Image Loaded with Invalid Signature
- Potential Masquerading as Browser Process
- Potential Masquerading as Business App Installer
- Potential Masquerading as Communication Apps
- Potential Masquerading as System32 Executable
- Potential Masquerading as VLC DLL
- Startup Folder Persistence via Unsigned Process
- Suspicious Communication App Child Process
- Suspicious DLL Loaded for Persistence or Privilege Escalation
- Suspicious Outlook Child Process
- Unsigned DLL Loaded by Svchost
- Unsigned DLL Side-Loading from a Suspicious Folder
- Untrusted Driver Loaded