Hello Mayra. It's not unusual to have more than one taskeng.exe running, especially if you subscribe to RSS feeds or have multiple tasks scheduled to run at or near the same time. If you google "multiple taskeng.exe processes" you'll find a lot of folks having the same issue going back to Vista. One example of multiple taskeng.exe: your computer automatically updates your virus data base at the same time a disk defrag is scheduled.
To see what tasks are schedule to run open Task Scheduler by either typing "task" into the Start Menu search bar, or by opening All Programs - Accesories - System Tools. You can check in the Task Scheduler Library (make sure the Show Hidden Tasks option is checked.) This tutorial, especially the part about editing or changing tasks, gives more info: Task Scheduler - Create New Task
If you're concerned about malware I'd run a full scan with your antimalware program of choice. Then I'd run a couple of free on-demand scanners like Malwarebytes
, Comodo Cleaning Essentials
, etc. No antimalware program is 100% effective 100% of the time. If there was such a product we'd all be using it and everyone else would be out of business.