1type: trigger
2name: sigmahq/proc_creation_win_schtasks_system
3description: |
4  Detects the creation or update of a scheduled task to run with "NT AUTHORITY\SYSTEM" privileges
5filter: |
6  (evt.Meta.service == 'sysmon' && evt.Parsed.EventID == '1') && (evt.Parsed.Image endsWith '\\schtasks.exe' && (evt.Parsed.CommandLine contains ' /change ' || evt.Parsed.CommandLine contains ' /create ') && evt.Parsed.CommandLine contains '/ru ' && (evt.Parsed.CommandLine contains 'NT AUT' || evt.Parsed.CommandLine contains ' SYSTEM ') && not (evt.Parsed.Image endsWith '\\schtasks.exe' && evt.Parsed.CommandLine contains '/TN TVInstallRestore' && evt.Parsed.CommandLine contains '\\TeamViewer_.exe' || evt.Parsed.CommandLine contains '/Create /F /RU System /SC WEEKLY /TN AviraSystemSpeedupVerify /TR ' || evt.Parsed.CommandLine contains ':\\Program Files (x86)\\Avira\\System Speedup\\setup\\avira_speedup_setup.exe' || evt.Parsed.CommandLine contains '/VERIFY /VERYSILENT /NOSTART /NODOTNET /NORESTART" /RL HIGHEST'))
7blackhole: 2m
8#status: test
9labels:
10  service: windows
11  confidence: 1
12  spoofable: 0
13  classification:
14   - attack.t1053.005
15
16  label: "Schtasks Creation Or Modification With SYSTEM Privileges"
17  behavior : "windows:audit"
18  remediation: false
19
20scope:
21  type: ParentProcessId
22  expression: evt.Parsed.ParentProcessId
23
24