ATT&CK coverage › Technique
Masquerading: Rename Legitimate Utilities T1036.003
Adversaries may rename legitimate / system utilities to try to evade security mechanisms concerning the usage of those utilities. Security monitoring and control mechanisms may be in place for legitimate utilities adversaries are capable of abusing, including both built-in binaries and tools such as PSExec, AutoHotKey, and IronPython. It may be possible to bypass those security mechanisms by renaming the utility prior to utilization (ex: rename <code>rundll32.exe</code>). An alternative case occurs when a legitimate utility is copied or moved to a different directory and renamed to avoid detections based on these utilities executing from non-standard paths.
Events covered
7 catalog events are tagged with this technique by at least one rule.
Authoring guide
Patterns shared across the 26 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized 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 (14 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 (399 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.
Common exclusions (1 distinct)
Field/operator/value combinations that rules under this technique routinely exclude (top-level not() clauses). 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.
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 24 rules
- File Download Via Bitsadmin
- File Download Via Bitsadmin To A Suspicious Target Folder
- File With Suspicious Extension Downloaded Via Bitsadmin
- LOL-Binary Copied From System Directory
- Potential Defense Evasion Via Binary Rename
- Potential Defense Evasion Via Rename Of Highly Relevant Binaries
- Potential Homoglyph Attack Using Lookalike Characters
- Potential Homoglyph Attack Using Lookalike Characters in Filename
- Potential PendingFileRenameOperations Tampering
- Potential WerFault ReflectDebugger Registry Value Abuse
- PUA - Potential PE Metadata Tamper Using Rcedit
- Remote Access Tool - Renamed MeshAgent Execution - Windows
- Renamed BrowserCore.EXE Execution
- Renamed Jusched.EXE Execution
- Renamed Msdt.EXE Execution
- Renamed Office Binary Execution
- Renamed Powershell Under Powershell Channel
- Renamed ProcDump Execution
- Renamed Schtasks Execution
- Suspicious Copy From or To System Directory
- Suspicious Download From Direct IP Via Bitsadmin
- Suspicious Download From File-Sharing Website Via Bitsadmin
- Suspicious Start-Process PassThru
- Windows Processes Suspicious Parent Directory