1type: trigger
2name: sigmahq/proc_creation_win_cmd_mklink_osk_cmd
3description: |
4  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.
5filter: |
6  (evt.Meta.service == 'sysmon' && evt.Parsed.EventID == '1') && ((evt.Parsed.Image endsWith '\\cmd.exe' || evt.Parsed.OriginalFileName == 'Cmd.Exe') && evt.Parsed.CommandLine contains 'mklink' && evt.Parsed.CommandLine contains '\\osk.exe' && evt.Parsed.CommandLine contains '\\cmd.exe')
7blackhole: 2m
8#status: test
9labels:
10  service: windows
11  confidence: 1
12  spoofable: 0
13  classification:
14   - attack.t1546.008
15
16  label: "Potential Privilege Escalation Using Symlink Between Osk and Cmd"
17  behavior : "windows:audit"
18  remediation: false
19
20scope:
21  type: ParentProcessId
22  expression: evt.Parsed.ParentProcessId
23
24