Detection rules › Sigma
Potential Privilege Escalation Using Symlink Between Osk and Cmd
Detects the creation of a symbolic link between "cmd.exe" and the accessibility on-screen keyboard binary (osk.exe) using "mklink". This technique provides an elevated command prompt to the user from the login screen without the need to log in.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1546.008 Event Triggered Execution: Accessibility Features |
| Privilege Escalation | T1546.008 Event Triggered Execution: Accessibility Features |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 1 | Process creation |
Stages and Predicates
Stage 1: all of selection_img
or:
Image|endswith: '\cmd.exe'
OriginalFileName: Cmd.Exe
Stage 2: all of selection_cli
CommandLine|contains: '\cmd.exe'
CommandLine|contains: '\osk.exe'
CommandLine|contains: mklink
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 |
|
Image | ends_with |
|
OriginalFileName | eq |
|