hechshers.info provides information about known hechshers. This page records information about logos which are not hechshers. For example one is said to be a commercial trademark.
There needs to be a hechsher recording supervision from an authority which you recognise and trust.
ADDITION: Certain civil laws exist which
prohibit the use of the phrase kosher in a product's labelling, unless it can be shown that the product conforms to Jewish dietary laws; however, the legal qualifications for conforming to Jewish dietary laws are often defined differently in different jurisdictions.
Whether the legal qualifications for conformance are good enough, you will have to ask your OR.