Detection rules › Sigma
Suspicious Csi.exe Usage
Csi.exe is a signed binary from Microsoft that comes with Visual Studio and provides C# interactive capabilities. It can be used to run C# code from a file passed as a parameter in command line. Early version of this utility provided with Microsoft “Roslyn” Community Technology Preview was named 'rcsi.exe'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1072 Software Deployment Tools |
| Defense Evasion | T1218 System Binary Proxy Execution |
| Lateral Movement | T1072 Software Deployment Tools |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 1 | Process creation |
Stages and Predicates
Stage 1: all of selection_img
or:
Image|endswith: '\csi.exe'
Image|endswith: '\rcsi.exe'
OriginalFileName: csi.exe
OriginalFileName: rcsi.exe
Stage 2: all of selection_cli
Company: 'Microsoft Corporation'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Company | eq |
|
Image | ends_with |
|
OriginalFileName | eq |
|