Comment Bot Question

Are comment bots legal? For a steam profile comment push? Or can something happen to you?

I'm level 202 on steam, would like to boost my comments but dunno if it's allowed.

I don't think steam have their own "Anti-Spam" or any real "Security". There has never been a case where a steam account was taken down entirely for bots. If they don't care about SAM then i don't think they would care about you using comment bots.