Spam from OC forms

For few months i have lots of spam from any kind of form (custom, magic form plugin, contact form plugin). Fields are properly validated.

Do you have the same? How to prevent this?

Content example below:
|Imienazwisko:|zaANnvSbCFFfvXCMwYXPBHE|
|Email:|afa.xu.t.e.si.068@gmail.com|
|Telefon:|7739360336|
|Zapytanie:|xDRWfbtvjtFUlubVwOoD|