Detection rules › Sigma
Potential File Download Via MS-AppInstaller Protocol Handler
Detects usage of the "ms-appinstaller" protocol handler via command line to potentially download arbitrary files via AppInstaller.EXE The downloaded files are temporarly stored in ":\Users%username%\AppData\Local\Packages\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe\AC\INetCache<RANDOM-8-CHAR-DIRECTORY>"
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Defense Evasion | T1218 System Binary Proxy Execution |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 1 | Process creation |
| Security-Auditing | 4688 | A new process has been created. |
Stages and Predicates
Stage 1: selection
CommandLine|contains: http
CommandLine|contains: 'ms-appinstaller://?source='
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 |
|---|---|---|
CommandLine | match |
|