No, I only played dota 2 from the past month did no other steam related activities.
Today at 5: 00 am I was unable to login. When i checked my mail i had message at 10 pm yesterday that my email has been changed. Also I have steam security on, so when some one tries to login from new PC it sends a verification code, I didnt receive that too. The e-mail was changed bypassing it.
BTW my e-mail is not hacked (though i changed the pwd anyway). Dont understand how they got through.
Also recently I used using Dotabuff, which asks for steam login credentials to login. However I have been using it since 2012 (though not regularly)