John Mueller from Google said that generally Google is quicker at processing malware reviews than hacked content reviews. John said on Twitter "Malware reviews are generally really fast; hacked content can take a bit longer."
Malware is when you have some some of malware installed on your web site, removing it and submitting a reconsideration request will reverse that manual action. Hacked content is when someone hacks your site and injects content on new or existing pages, removing the hacked content often takes longer and when you submit a reconsideration request, that review can take longer.
Here are the tweets:
Malware or hacked content? Malware reviews are generally really fast; hacked content can take a bit longer.
— 🍌 John 🍌 (@JohnMu) November 7, 2019
Usually just hacked content wouldn't show an interstitial, it would just show the note in search. If it's showing an interstitial, that would go through the malware side, where reviews are generally pretty quick.
— 🍌 John 🍌 (@JohnMu) November 7, 2019
Either way - both are fairly quick to resolve with Google search. Sometimes a day or so.
Forum discussion at Twitter.