What threat is out there?

Why it is advised to visit this site only in incognito mode?
Site -http://ir-na.amazon-adsystem.com/s/ads-common.js
even this is advised against: -https://duckduckgo.com/?q=http%3A%2F%2Fir-na.amazon-adsystem.com%2Fs%2Fads-common.js&atb=v150-1

polonus

Here nothing being flagged: https://www.virustotal.com/gui/url/e081343cc60112b48ba7de42b9b6a3446a19696b8b8ddcac60444ea6e249d8c4/detection
From DOM-XSS scanning we see relations to -http://35stupenek.ru/wp-content/themes/Direct/js/menu-hover.js?ver=4.4.2
& -http://35stupenek.ru/wp-content/themes/Direct/js/menu-hover.js?ver=4.4.2
Also consider: https://www.shodan.io/host/52.94.229.212
No alerts: https://urlquery.net/report/c036e80d-8679-44c3-9279-9c5351a495f8

Don’t know what DrWeb’s got against that address to only open it up through anonimity mode?
See: https://toolbar.netcraft.com/site_report?url=ir-na.amazon-adsystem.com%2Fs%2Fads-common.js
& https://www.virustotal.com/gui/ip-address/52.94.229.212/relations = with Android adware Admob detections
Consider re-writes here: https://atlas.eff.org//domains/amazon-adsystem.com.html
Problematic hosts there: https://github.com/hackers-terabit/ggitm/blob/master/rules/Amazon-Adsystem.com.xml
On markmonitor abuse there: https://otx.alienvault.com/indicator/domain/ir-na.amazon-adsystem.com
What for awhitelisted domain?

polonus

Here we find more information about Amazon Adsystem as tracker:
https://whotracks.me/trackers/amazon_adsystem.html and qualified as very prevalent

pol