Where to find secure.eyereturn.com appearing on GTmetrix

Question

I recently decided to test run my website to see how its performing using GTmetrix and the result is very poor (PageSpeed Score - 49%, YSlow Score - 47%). I am seeing a host of issues resorted but one is a bit confusing to me.

Leverage browser caching for the following cacheable resources:

https://quickresource.eyereturn.com/eyebuild/eyebuild_1_19.js
(expiration not specified)
https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/GC.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/actual-offer.jpg
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/and.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/border300x250.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/close.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/copy_01.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/copy_02.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/copy_05.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/cta.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/dot.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/heart_l.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/heart_r.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/logo.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/logo_02.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/mobile.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/offer.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/images/offer_link.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_300x250_EN_v1/index_edge.js
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/GC.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/actual-offer.jpg
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/and.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/bbym-blk.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/bbym.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/borde728x90.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/close.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/copy_01.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/copy_02.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/copy_03.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/copy_05.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/cta.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/dot.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/heart_l.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/heart_r.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/logo.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/mobile.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/offer.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/images/offer_link.png
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https://secure.eyereturn.com/25127/0324_FF_Offer_728x90_EN_v1/index_edge.js
(expiration not specified)
https://animate.adobe.com/runtime/5.0.0/edge.5.0.0.min.js (15 minutes)
https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js (1
hour) https://pagead2.googlesyndication.com/pagead/osd.js (1 hour)
https://www.google-analytics.com/analytics.js (2 hours)P

What is "secure.eyereturn.com" and where I can find it and remove it?

Answer 1

This comes from your AdSense ads. You can't control how ad networks specify their cache control headers. Your only real option to "fix" this problem is to remove the ads.

PageSpeed, GTmetrix and YSlow are a bit dumb about this. They really shouldn't be reporting the cache control headers of third party resources. Especially when the resources are loaded asynchronously (as is the case with AdSense).