Israel-based ad startup ClarityRay announced on its website that it has been acquired by Yahoo.

A Yahoo spokesperson sent me the following statement confirming the deal:

We’ve been working on building up security capabilities and making Yahoo a safer place for users and partners. Advertising is an essential part of our business here at Yahoo, and we’re committed to getting it right. ClarityRay is a company with deep expertise in ad-malware detection and prevention. The bottom line for Yahoo is that search is going to get better and safer for users, and advertising will become more reliable and profitable for partners.

I first wrote about ClarityRay two years ago after it raised $500,000 in funding from its chairman Saar Wilf. At the time, the company offered tools for online publishers to circumvent ad blockers — CEO Ido Yablonka told me that his goal was to help publishers make money without ignoring the concerns of the “ad intolerant.”

Since then, however, as the Yahoo statement suggests, ClarityRay’s focus has moved away from ad blocking to ad security and fraud detection. (I’m trying to get more detail about what the company has been up to and will update if I find out.)

The ClarityRay announcement doesn’t say anything about the terms of the deal or offer specifics about the extent to which Yahoo will be using the company’s technology. The startup writes:

Joining Yahoo now will allow us to make use of that momentum and take the next steps (or rather, leaps) towards that vision, and we couldn’t be more excited. This once-in-a-lifetime opportunity enables the mass scaling of our technology, impact and ideas to the absolute forefront of our field, while working with an amazing team who shares our passion. We’re proud to call Yahoo ‘home’.

Yahoo has become notably acquisitive since Marissa Mayer became CEO two years ago, something that has been credited with reinvigorating the company while also drawing its share of criticism.