Google has ported another feature from the old Search Console to the new, the security issues section. Google said on Twitter "We hope you don't need to use a Security Issues tab" but if you do, it has been migrated to the new Search Console.
Google made a new section named "Security & Manual Actions" in the side bar, it was previous just "manual actions." In that section is a link to see "Security Issues." Here is a screen shot:
Hopefully after you click on it, you see this:
Here is an example screen shot Google shared with less exciting news:
You can learn more about the types of security issues would post here in this help doc at Google.
Forum discussion at Twitter.