I have recently found black stains on the kraft paper, just wondering if its kind of growth, etc.
It is hard to tell from MI, Moshe.
And, welcome to our forum…hope to hear from you more around here.
The pattern is similar to what I see with thermal imaging which is associated with air flow between the insulation ans the Sheetrock (improper install allows air flow).
Only you can determine what it is on site.
In addition, That doesn’t look like a crawlspace to me.