No, not all sins are evil, but it depends on how you define "evil".
In our Torah, sinful people are called Reshaim (Evil),
but in the terms of our days, evil is something against humanity, something that is opposed to "good".
So if you are talking about evil of our days, not all the sins are evil, not at all, for example eating not kosher food (did it hurt anyone around you?)
or desecrating Shabat.