System Binary Proxy Execution: Regsvr32 T1218.010

Events covered

11 catalog events are tagged with this technique by at least one rule.

Authoring guide

Patterns shared across the 50 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 (28 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 (534 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 (241 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 19 rules

• DNS Query Request By Regsvr32.EXE
• HTML Help HH.EXE Suspicious Child Process
• Network Connection Initiated By Regsvr32.EXE
• Potential APT-C-12 BlueMushroom DLL Load Activity Via Regsvr32
• Potential EmpireMonkey Activity
• Potential Regsvr32 Commandline Flag Anomaly
• Potentially Suspicious Child Process Of Regsvr32
• Potentially Suspicious Regsvr32 HTTP IP Pattern
• Potentially Suspicious Regsvr32 HTTP/FTP Pattern
• Regsvr32 DLL Execution With Suspicious File Extension
• Regsvr32 Execution From Highly Suspicious Location
• Regsvr32 Execution From Potential Suspicious Location
• Scripting/CommandLine Process Spawned Regsvr32
• Suspicious HH.EXE Execution
• Suspicious Microsoft Office Child Process
• Suspicious Regsvr32 Execution From Remote Share
• Suspicious WMIC Execution Via Office Process
• Suspicious WmiPrvSE Child Process
• Unsigned DLL Loaded by Windows Utility

Elastic 17 rules

• Delayed Execution via Ping
• Execution from Unusual Directory - Command Line
• Execution of Persistent Suspicious Program
• Network Connection via Registration Utility
• Potential Command and Control via Internet Explorer
• Service Control Spawned via Script Interpreter
• Suspicious .NET Code Compilation
• Suspicious Execution from a Mounted Device
• Suspicious Explorer Child Process
• Suspicious JetBrains TeamCity Child Process
• Suspicious Managed Code Hosting Process
• Suspicious MS Office Child Process
• Suspicious MS Outlook Child Process
• Suspicious PDF Reader Child Process
• Suspicious Script Object Execution
• Suspicious Windows Command Shell Arguments
• Unusual Network Activity from a Windows System Binary

Splunk 12 rules

• Detect Regsvr32 Application Control Bypass
• Malicious InProcServer32 Modification
• regsvr32 Execution (PowerShell)
• regsvr32 Execution (Sysmon)
• regsvr32 Execution (Windows Event Log)
• regsvr32 Referencing Unusual Paths (Sysmon)
• regsvr32 Referencing Unusual Paths (Windows Event Log)
• Regsvr32 Silent and Install Param Dll Loading
• Regsvr32 with Known Silent Switch Cmdline
• Suspicious Regsvr32 Register Suspicious Path
• Windows IOBit Unlocker Extension DLL Registration via Regsvr32
• Windows Regsvr32 Renamed Binary

Kusto 2 rules

• Regsvr32 Rundll32 Image Loads Abnormal Extension
• Regsvr32 Rundll32 with Anomalous Parent Process