Anything is possible, I suppose, but it is unlikely that eBay itself is actually trying to deliver a virus to you.
Some more likely possibilities:
A dodgy third-party advertisement may be triggering the warning. Hard to diagnose because different users often get different ads on the same page -- even reloading the page can shuffle the ads in some cases. Which ads you do see may depend on many factors including your location and past browsing history. Ad blockers can help with this.
A false alarm by your virus program or browser. Sometimes something innocent gets mistaken for a potential virus. Usually it is better to be safe than sorry.
Adware or malware on your device may be trying to deliver an ad that is infected. In some cases, malware can hide until the user tries to navigate to a popular site, then an ad delivery is attempted. eBay and Yahoo are two very common targets for such browser-hijacking adware, which often are seen promoting scam gift card offers or bogus surveys.
An adware scan might be worth trying. Adwcleaner by Malwarebytes is one option, but there are others.
