Most often, this is harmless.
/sbin/ifinfo is executed, when a user does a 'show interface' command. Because ifinfo returned error (status 1), it likely means someone did 'show interface' for an interface that wasn't found. Like a typo, or an interface that doesn't exist on the router.
If you can rule out someone doing the above, then I would look for any other errors/unusual logs around that.
Ben