Windows Defender and *.zip.zip.zip.zip fun

[xorbe]

So, in Linux (via VirtualBox) I put 100 x 4GB files of zeros into a zip file, which was about 400MB. Zipping it 3 more times got the file down to 39KB. (Any more made the file bigger).

I made the mistake of trying to open that file in Windows ... Defender brings the computer to a grinding halt trying to unzip everything for scanning! I wound up disabling Defender and having to reboot to reclaim my cpu time / ssd access.

Wonder if this would take down email scanners ...

 

[socK]

I'm a little surprised it's not detected as a zip bomb.

 

[xorbe]

Ooh, it has an official name. Wikipedia describes the exact nested zip file I made. Except their 42KB file expands to 4 petabytes.

Interesting, zip files that unzip to infinite data, and zip files that recurse folders infinitely, those must be hand crafted.

 

[primetime]

think ill hold off on your fun zip bomb

 

[xorbe]

think ill hold off on your fun zip bomb

I found the "4PB" 42kb 42.zip file online (password 42) and Windows had trouble deleting it even though I only opened the first level. It's still trying to peer inside even with Defender turned off or something ...

 

[SvenBent]

so far there is only one example of infinity loop archive. its used gz compression and decompressed into the exact same file so it can go on forever

 

[PornoSatan]

I made a custom bat file one time that Windows Defender flagged, I forget what kind of code I added but Windows Defender went off on me for doing it.