Sorry for the delay in replying, had to go out of town after I posted originally. Here is the extended information provided by Yandex, but the more I look into it, the more I think it is a false positive.
More information
Yandex periodically checks websites to warn users about harmful webpages. The last check (less than a week ago) showed that this site contains malware. This can happen either in accordance with the owner's intent or due to the tampering of fraudsters.
Malware:
How Yandex verifies sites
Here is a good page with details regarding Mal/Iframe-W from Sophos, hopefully it helps pinpoint the possible source if you haven't already.
https://nakedsecurit...hack-nice-pack/
Best Regards,
- ouiji