Solving Kusto Detective Academy Case 4

Tom Zika wears a trench coat and works out of a run-down office in a mess of a town, all in black and white:

Someone hacked into Digitown’s municipality, stole classified documents, and vanished. All we have is 30 days of router logs and a lookup table. Time to find a needle in 45 million rows of hay.

I really like the work the Kusto team has put into Kusto Detective Academy. Tom’s blog post is a spoiler if you want to answer it yourself, of course.